1. Field of the Invention
The present invention provides heterocycle carboxamide derivatives. These compounds are useful as antiviral agents, in particular, as agents against viruses of the herpes family.
2. Technology Description
The herpesviruses comprise a large family of double stranded DNA viruses. They are also a source of the most common viral illnesses in man. Eight of the herpesviruses, herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), varicella zoster virus (VZV), human cytomegalovirus (HCMV), Epstein-Barr virus (EBV), and human herpes viruses 6, 7, and 8 (HHV-6, HHV-7, and HHV-8), have been shown to infect humans.
HSV-1 and HSV-2 cause herpetic lesions on the lips and genitals, respectively. They also occasionally cause infections of the eye and encephalitis. HCMV causes birth defects in infants and a variety of diseases in immunocompromised patients such as retinitis, pneumonia, and gastrointestinal disease. VZV is the causative agent of chicken pox and shingles. EBV causes infectious mononucleosis. It can also cause lymphomas in immunocompromised patients and has been associated with Burkitt""s lymphoma, nasopharyngeal carcinoma, and Hodgkin""s disease. HHV-6 is the causative agent of roseola and may be associated with multiple sclerosis and chronic fatigue syndrome. HHV-7 disease association is unclear, but it may be involved in some cases of roseola. HHV-8 has been associated with Karposi""s sarcoma, body cavity based lymphomas, and multiple myeloma.
U.S. Pat. Nos. 5,753,666 and 5,891,878 and WO 97/04775 disclose specific 1-alkyl-substituted-quinolone-3-carboxamides that are alleged to have therapeutic utility via inhibition of Phosphodiesterase IV esterase and/or Tumor Necrosis factor activity.
Commonly assigned WO 00/40561 discloses quinolinecarboxamides as antiviral agents.
Commonly assigned WO 00/40563 discloses specific quinolinecarboxamides as antiviral agents.
Commonly assigned WO 00/53610 discloses 4-Oxo-4,7-dihydrothieno[2,3-b]pyridine-5-carboxamides as antiviral agents.
Commonly assigned WO99/32450 discloses specific 4-hydroxyquinoline-3-carboxamides and hydrazides as antiviral agents.
U.S. Pat. No. 5,945,431 discloses specific naphthyridine heterocyclic compounds having antiviral activity that are useful in the therapy and prophylaxis of cytomegalovirus (CMV) infection in mammals.
WO99/10347 discloses specific substituted 4-oxo-naphthyridine-3-carboxamides as brain receptor ligands having potential use in the treatment of central nervous system diseases and/or disorders.
WO098/19673 discloses specific heterocyclic agents for the treatment of diseases caused by viruses.
JP08301849 discloses specific heterocyclic agents useful as tachykinin receptor antagonists. They are suggested for use in treatment of the following diseases: inflammation, allergic diseases, CNS disorders, digestive system disorders, urinary tract disorders, cardiovascular diseases immunopathy. The reference suggests that the inventive compounds can be used to treat herpes, but classifies herpes as either an inflammation or allergic reaction disease. The reference does not suggest that the compounds can be used to treat infectious diseases.
JP07033729 discloses specific N-cyano-Nxe2x80x2-substituted-arylcarboxyimidamide compounds exhibiting K+ channel opening effects and having hypotensive action and coronary vasodilating action.
WO 00/40562 discloses novel 2-oxoquinolines as selective peripheral cannabinoid receptor modulators).
WO 97/34894 discloses Naphthyridine derivatives and their analogues inhibiting cytomegalovirus.
Despite the above teachings, there still exists a need in the art for novel compounds that demonstrate desirable antiviral activity.
In accordance with the present invention, novel compounds which demonstrate antiviral activity are provided. More specifically, the compounds are specific heterocycle carboxamide derivatives which are useful as antiviral agents, particularly against herpesviruses.
Even more specifically, the present invention provides a compound of formula I, 
wherein,
X is Cl, Br, F, CN, or NO2;
G is
(a) C1-4alkyl which is fully saturated or partially unsaturated and is substituted by hydroxy, or
(b) C1-4alkyl substituted by NR1R2 or 4-tetrahydropyran;
R1 is C2-7alkyl substituted by hydroxy, C1-4alkoxy, heteroaryl, or aryl;
R2 is hydrogen or C1-7alkyl;
or R1 and R2 together with the nitrogen to which they are attached form morpholine which may be optionally substituted by aryl or C1-7alkyl; or pyrrolidine substituted by hydroxy;
W is a heterocycle of formula W1, W2, W3, W4, W5, W6, W7, W8, W9, W10, W11, W12, W13, W14, W15, W16, W17, W18, W19, W20, W21 or W22
A is CR4 or nitrogen;
B is CR5 or nitrogen;
C is CR6 or nitrogen;
D is CR8 or nitrogen;
E and F are such that one is oxygen and the other is C(xe2x95x90O);
J is NR7 or oxygen;
K and L are defined such that
(a) K is CR5 and L is CR6, or
(b) K is absent and L is sulfur;
M is oxygen, sulfur, or S(O)m;
Y is oxygen or sulfur;
with the provisos that:
when W is of formula W3 then at least one of A, B, or C is nitrogen and R7 is other than H, and if C is nitrogen then A, B or A and B are nitrogen;
when W is of formula W4 then at least one of A, B, or C is nitrogen;
when W is of formula W9 then at least two of A, B, or C is nitrogen;
when W is of formula W16 and J is oxygen then R7 is other than H;
when W is of formula W16 then J is other than NH;
when W is of formula W19, A is nitrogen, G is morpholinylmethyl, and X is chloro then R8 is other than H;
when W is of formula W20 then at least one of A or D is nitrogen;
R4 is H, halogen, or C1-4alkyl optionally substituted by one to three halogens;
R5 is
(a) H,
(b) halo,
(c) OR12,
(d) SR12,
(e) C1-7alkyl which may be partially unsaturated and optionally substituted by one or more substituents selected from OR12, SR12, NR10R11, or halo,
(f) C3-8cycloalkyl which may be partially unsaturated and is optionally substituted by one or more substituents selected from halogen, OR12, SR12, or NR10R11,
(g) (Cxe2x95x90O)R9,
(h) S(O)mR9,
(i) (Cxe2x95x90O)OR2,
(j) NHSO2R9,
(k) nitro, or
(l) cyano;
R6 is
(a) H,
(b) halo,
(c) aryl,
(d) het,
(e) OR12,
(f) SR12,
(g) C1-7alkyl which may be partially unsaturated and optionally substituted by one or more substituents selected from OR12, SR12, NR10R11, aryl, halo, C3-8cycloalkyl optionally substituted by OR12, or het attached through a carbon atom,
(h) NR10R11,
(i) C3-8cycloalkyl which may be partially unsaturated and is optionally substituted by one or more substituents selected from halogen, OR12, SR12, or NR10R11,
(j) (Cxe2x95x90O)R9,
(k) S(O)mR9,
(l) (Cxe2x95x90O)OR2,
(m) NHSO2R9,
(n) nitro, or
(o) cyano;
R7is
(a) H,
(b) C1-7alkyl which may be partially unsaturated and optionally substituted by one or more substituents selected from OR12, SR12, NR10R11, or halo,
(c) C3-8cycloalkyl which may be partially unsaturated and is optionally substituted by one or more substituents selected from halogen, OR12, SR12, or NR10R11,
(d) aryl, or
(e) het;
R8 is
(a) H,
(b) C1-7alkyl which may be partially unsaturated and optionally substituted by one or more substituents selected from OR12, SR12, NR10R11, or halo,
(c) OR12, or
(d) SR12;
R9 is
(a) C1-7alkyl,
(b) NR10R11,
(c) aryl, or
(d) het, wherein said het is bound through a carbon atom;
R10 and R11 are independently
(a) H,
(b) aryl,
(c) C1-7alkyl which may be partially unsaturated and is optionally substituted by one or more substituents selected from CONR2R2, CO2R2, het, aryl, cyano, or halo,
(d) C2-7alkyl which may be partially unsaturated and is substituted by one or more substituents selected from NR2R2, OR2, or SR2,
(e) C3-8cycloalkyl which may be partially unsaturated and is optionally substituted by one or more substituents selected from halogen, OR2, SR2, or NR2R2, or
(f) R10 and R11 together with the nitrogen to which they are attached form a het;
R12 is
(a) H,
(b) aryl,
(c) het
(d) C1-7alkyl optionally substituted by aryl, or halogen,
(e) C2-7alkyl substituted by OR2, SR2, or NR2R2, or
(f) C3-8cycloalkyl which may be partially unsaturated and is optionally substituted by one or more substituents selected from halogen, OR2, SR2, or NR2R2;
each m is independently 1 or 2;
aryl is a phenyl radical or an ortho-fused bicyclic carbocyclic radical wherein at least one ring is aromatic, and aryl maybe optionally substituted with one or more substituents selected from halo, OH, cyano, NR2R2, CO2R2, CF3, C1-6alkoxy, and C1-6 alkyl which maybe further substituted by one to three SR2, NR2R2, OR2, or CO2R groups;
het is a four- (4), five- (5), six- (6), or seven- (7) membered saturated or unsaturated heterocyclic ring having 1, 2, or 3 heteroatoms selected from oxygen, sulfur, or nitrogen, which is optionally fused to a benzene ring, or any bicyclic heterocycle group, and het may be optionally substituted with one or more substituents selected from halo, OH, cyano, phenyl, CO2R2, CF3, C1-6alkoxy, oxo, oxime, and C1-6 alkyl which may be further substituted by one to three SR2, NR2R2, OR2, or CO2R2 groups;
halo or halogen is F, Cl, Br, I;
1 represents the point of attachment between W and G;
2 represents the point of attachment between W and the carbonyl group of Formula (I);
and a pharmaceutically acceptable salt thereof.
In particularly preferred embodiments, X is Cl and G is 4-morpholinylmethyl.
Another embodiment of the present invention provides a pharmaceutical composition comprising a compound of formula (I) as defined above, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier. In preferred embodiments, the composition preferably comprises a therapeutically effective amount of the compound or salt.
Still another embodiment of the present invention provides a method for treating a disease or condition in a mammal caused by a viral infection, particularly a herpes viral infection, comprising administering to the mammal a therapeutically effective amount of a compound of formula (I) or a pharmaceutically acceptable salt thereof.
A further embodiment of the present invention comprises the use of a compound of formula (I) or a pharmaceutically acceptable salt thereof to prepare a medicament for treating or preventing diseases or disorders caused by a viral infection, and particularly a herpes viral infection.
A final embodiment of the present invention comprises a method for inhibiting a viral DNA polymerase, comprising contacting (in vitro or in vivo) the polymerase with an effective inhibitory amount of a compound of formula (I) or a pharmaceutically acceptable salt thereof.
An object of the present invention is to provide novel compounds having biological activity.
A further object of the present invention is to provide novel pharmaceutical compositions.
Still another object of the present invention is to provide a method for treating a disease or condition in a mammal caused by a viral infection, particularly a herpes virus infection.
Another object of the present invention is to provide a method for inhibiting a viral DNA polymerase.
Still another object of the present invention is to provide novel intermediates useful for the preparation of the compound of the present invention.
These, and other objects, will readily be apparent to those skilled in the art as reference is made to the detailed description of the preferred embodiment.
In describing the preferred embodiment, certain terminology will be utilized for the sake of clarity. Such terminology is intended to encompass the recited embodiment, as well as all technical equivalents which operate in a similar manner for a similar purpose to achieve a similar result.
1. Terminology Definitions
The following definitions are used, unless otherwise described: halo is fluoro, chloro, bromo, or iodo. Alkyl denotes both straight and branched groups; but reference to an individual radical such as xe2x80x9cpropylxe2x80x9d embraces only the straight chain radical, a branched chain isomer such as xe2x80x9cisopropylxe2x80x9d being specifically referred to. When alkyl can be partially unsaturated, the alkyl chain may comprise one or more (e.g., 1, 2, 3, or 4) double or triple bonds in the chain.
Aryl denotes a phenyl radical or an ortho-fused bicyclic carbocyclic radical wherein at least one ring is aromatic. Het is a four- (4), five- (5), six- (6), or seven- (7) membered saturated or unsaturated ring containing 1, 2 or 3 heteroatoms selected from the group consisting of non-peroxide oxygen, sulfur, and nitrogen, which is optionally fused to a benzene ring, or any bicyclic heterocyclic group. Het includes xe2x80x9cheteroarylxe2x80x9d, which encompasses a radical attached via a ring carbon of a monocyclic aromatic ring containing five or six ring atoms consisting of carbon and 1, 2, 3, or 4 heteroatoms each selected from the group consisting of non-peroxide oxygen, sulfur, and N(X) wherein X is absent or is H, O, C1-4alkyl, phenyl or benzyl.
It will be appreciated by those skilled in the art that compounds of the invention having a chiral center may exist in and be isolated in optically active and racemic forms. Some compounds may exhibit polymorphism. It is to be understood that the present invention encompasses any racemic, optically-active, polymorphic, tautomeric, or stereoisomeric form, or mixture thereof, of a compound of the invention, which possesses the useful properties described herein, it being well known in the art how to prepare optically active forms (for example, by resolution of the racemic form by recrystallization techniques, by synthesis from optically-active starting materials, by chiral synthesis, or by chromatographic separation using a chiral stationary phase) and how to determine antiviral activity using the standard tests described herein, or using other similar tests which are well known in the art.
The carbon atom content of various hydrocarbon-containing moieties is indicated by a prefix designating a lower and upper number of carbon atoms in the moiety, i.e., the prefix Ci-j indicates a moiety of the integer xe2x80x9cixe2x80x9d to the integer xe2x80x9cjxe2x80x9d carbon atoms, inclusive. Thus, for example, C1-7alkyl refers to alkyl of one to seven carbon atoms, inclusive.
The compounds of the present invention are generally named according to the IUPAC or CAS nomenclature system. Abbreviations which are well known to one of ordinary skill in the art may be used (e.g. xe2x80x9cPhxe2x80x9d for phenyl, xe2x80x9cMexe2x80x9d for methyl, xe2x80x9cEtxe2x80x9d for ethyl, xe2x80x9chxe2x80x9d for hour or hours and xe2x80x9crtxe2x80x9d for room temperature).
Specific and preferred values listed below for radicals, substituents, and ranges, are for illustration only; they do not exclude other defined values or other values within defined ranges for the radicals and substituents. The compounds of the invention include compounds of formula (I) having any combination of the values, specific values, more specific values, and preferred values described herein.
Mammal denotes human and animals, specifically including food animals and companion animals.
2. The Invention
The present invention comprises compounds of formula (I) as defined above, and their pharmaceutically acceptable salts.
For the compounds of formula (I), alkyl can be methyl, ethyl, propyl, isopropyl, butyl, iso-butyl, sec-butyl, pentyl, 3-pentyl, hexyl, heptyl, etc.; C3-8cycloalkyl can be cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, or cyclooctyl; alkoxy can be methoxy, ethoxy, propoxy, isopropoxy, butoxy, iso-butoxy, sec-butoxy, pentoxy, 3-pentoxy, hexyloxy, 1-methylhexyloxy, or heptyloxy; het can be azetidinyl, 3,3-dihydroxy-1-azetinyl, pyrrolidino, piperidino, morpholino, thiomorpholino, or heteroaryl; and heteroaryl can be furyl, imidazolyl, triazolyl, triazinyl, oxazoyl, isoxazoyl, thiazolyl, isothiazoyl, pyrazolyl, pyrrolyl, pyrazinyl, tetrazolyl, pyridyl, (or its N-oxide), thienyl, pyrimidinyl (or its N-oxide), indolyl, isoquinolyl (or its N-oxide) or quinolyl (or its N-oxide).
When alkyl is partially unsaturated, it can be vinyl, allyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1,3-butadienyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, 5-hexene-1-ynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl, or 5-hexynyl.
Specific examples of W 1 include, 
Specific examples of W3 include, 
Specific examples of W4 include, 
Specific examples of W6 include, 
Specific examples of W7 include, 
Specific examples of W8 include, 
Specific examples of W9 include, 
Specific examples of W10 include, 
Specific examples of W 11 include, 
Specific examples of W13 include, 
Specific examples of W14 include, 
Specific examples of W 16 include, 
Specific examples of W19 include, 
Specific examples of W20 include, 
Specific examples of W21 include, 
Specific examples of W22 include, 
Particularly preferred compounds are those where X is Cl and G is 4-morpholinylmethyl.
Examples of the present invention include, but are not limited to the following:
N-(4-chlorobenzyl)-5-hydroxy-3-(3-hydroxy-1-propynyl)-2-oxo-2H-chromene-6-carboxamide;
N-(4-chlorobenzyl)-5-hydroxy-3-(3-hydroxypropyl)-2-oxo-2H-chromene-6-carboxamide;
N-(4-chlorobenzyl)-5-hydroxy-3-(4-morpholinylmethyl)-2-oxo-2H-chromene-6-carboxamide;
N-(4-chlorobenzyl)-5-hydroxy-4-methyl-3,8-bis(4-morpholinylmethyl)-2-oxo-2H-chromene -6-carboxamide;
N-(4-chlorobenzyl)-5-hydroxy-3-(3-hydroxy-1-propynyl)-1-methyl-2-oxo-1,2-dihydro-6-quinolinecarboxamide;
N-(4-chlorobenzyl)-5-hydroxy-3-(3-hydroxypropyl)-1-methyl-2-oxo-1,2-dihydro-6-quinolinecarboxamide;
N-(4-chlorobenzyl)-5-hydroxy-1-methyl-3-(4-morpholinylmethyl)-2-oxo-1,2-dihydro -6-quinolinecarboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxy-1-propynyl)-1-methyl-4-oxo-1,4-dihydro[1,7]-naphthyridine-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxypropyl)-1-methyl-4-oxo-1,4-dihydro[1,7]-naphthyridine-3-carboxamide;
N-(4-chlorobenzyl)-8-ethoxy-6-(3-hydroxy-1-propynyl)-1-methyl-4-oxo-1,4-dihydro[1,7]naphthyridine-3-carboxamide;
N-(4-chlorobenzyl)-8-ethoxy-6-(3-hydroxypropyl)-1-methyl-4-oxo-1,4-dihydro[1,7]-naphthyridine-3-carboxamide;
N-(4-chlorobenzyl)-1-methyl-6-(4-morpholinylmethyl)-4-oxo-1,4-dihydro[1,7]-naphthyridine-3-carboxamide;
8-chloro-N-(4-chlorobenzyl)-1-methyl-6-(4-morpholinylmethyl)-4-oxo-1,4-dihydro -1,7]naphthyridine-3-carboxamide;
N-(4-chlorobenzyl)-8-ethoxy-1-methyl-6-(4-morpholinylmethyl)-4-oxo-1,4-dihydro[1,7]naphthyridine-3-carboxamide;
N-(4-chlorobenzyl)-1-methyl-6,8-bis(morpholin-4-ylmethyl)-4-oxo-1,4-dihydro-1,7-naphthyridine-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxypropyl)-1-methyl-4-oxo-1,4-dihydro[1,5]-naphthyridine-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxy-1-propynyl)-1-methyl4-oxo-1,4-dihydro[1,5]-naphthyridine-3-carboxamide;
N-(4-chlorobenzyl)-1-methyl-6-(4-morpholinylmethyl)-4-oxo-1,4-dihydro[1,5]-naphthyridine-3-carboxamide;
N-(4-chlorobenzyl)-1-methyl4-oxo-6-(tetrahydro-2H-pyran-4-ylmethyl)-1,4-dihydro[1,5]naphthyridine-3-carboxamide;
N-(4-chlorobenzyl)-8-ethyl-3-(4-morpholinylmethyl)-5-oxo-5,8-dihydropyrido[2,3-c] pyridazine-6-carboxamide;
N-(4-chlorobenzyl)-2-(3-hydroxypropyl)-5-methyl-8-oxo-5 ,8-dihydropyrido[3 ,2-d]-pyrimidine-7-carboxamide;
N-(4-chlorobenzyl)-2-(3-hydroxy-1-propynyl)-5-methyl-8-oxo-5,8-dihydropyrido-[3,2-d]pyrimidine-7-carboxamide;
N-(4-chlorobenzyl)-5-methyl-2-(4-morpholinylmethyl)-8-oxo-5 ,8-dihydropyrido[3,2-d]pyrimidine-7-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxy-1-propynyl)-1-methyl-4-oxo-1,4-dihydropyrido-[2,3-c]pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxypropyl)-1-methyl-4-oxo-1,4-dihydropyrido[2,3-c]-pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-1-methyl-6-(4-morpholinylmethyl)-4-oxo-1,4-dihydropyrido[2,3-c]pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-1-methyl4-oxo-6-(tetrahydro-2H-pyran-4-ylmethyl)-1,4-dihydro-pyrido[2,3-c]pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxypropyl)-4-oxo-1,4-dihydropyrido[3 ,4-e]pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxy-1-propynyl)-4-oxo-1,4-dihydropyrido[3,4-c]-pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxypropyl)-1-methyl-4-oxo-1,4-dihydropyrido[3,4-c]-pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxy-1-propynyl)-1-methyl-4-oxo-1,4-dihydropyrido-[3,4-c]pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-1-methyl-6-(4-morpholinylmethyl)-4-oxo-1,4-dihydropyrido[3,4-c]pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-6-(4-morpholinylmethyl)-4-oxo-1,4-dihydropyrido[3,4-c]-pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-7-(3-hydroxy-1-propynyl)-4-oxo-4H-pyrido [1,2-a]pyrimidine-3-carboxamidePNU;
N-(4-chlorobenzyl)-7-(3-hydroxypropyl)-4-oxo-4H-pyrido [1,2-a]pyrimidine-3-carboxamide;
N-(4-chlorobenzyl)-7-(4-morpholinylmethyl)-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxamide;
N-(4-chlorobenzyl)-4-hydroxy-7-(3-hydroxy-1-propynyl)-2-oxo-2H-pyrido[1,2-a]-pyrimidine-3-carboxamide;
N-(4-chlorobenzyl)-2-hydroxy-7-(3-hydroxypropyl)-4-oxo-4H-pyrido[1,2-a]-pyrimidine-3-carboxamide;
N-(4-chlorobenzyl)-7-(3-hydroxypropyl)4-oxo-4H-pyrazino[1,2-a]pyrimidine-3-carboxamide;
N-(4-chlorobenzyl)-7-(3-hydroxy-1-propynyl)4-oxo-4H-pyrazino[1,2-a]pyrimidine-3-carboxamide;
N-(4-chlorobenzyl)-7-(4-morpholinylmethyl)-4-oxo-4H-pyrazino[1,2-a]pyrimidine-3-carboxamide;
N-(4-chlorobenzyl)-7-(3-hydroxy-1-propynyl)-4-oxo-4H-pyrimido[1,2-b]pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-7-(3-hydroxypropyl)-4-oxo-4H-pyrimido[1,2-b]pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-4-oxo-7-(tetrahydro-2H-pyran-4-ylmethyl)-4H-pyrimido[1,2]-pyridazine-3-carboxamide; N-(4-chlorobenzyl)-7-(4-morpholinylmethyl)-4-oxo-4H-pyrimido [1,2-b]pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-7-(3-hydroxypropyl)-4-oxo-4H-pyrimido[1,2-a]pyrimidine-3-carboxamide;
N-(4-chlorobenzyl)-7-(3-hydroxy-1-propynyl)-4-oxo-4H-pyrimido[1,2-a]pyrimidine-3-carboxamide;
N-(4-chlorobenzyl)-4-oxo-7-(tetrahydro-2H-pyran-4-ylmethyl)-4H-pyriinido[1,2-a]-pyrimidine-3-carboxamide;
N-(4-chlorobenzyl)-7-(4-morpholinylmethyl)-4-oxo-4H-pyrimido[1,2-a]pyrimidine-3-carboxamide;
N-(4-chlorobenzyl)-2-(3-hydroxypropyl)-8-oxo-8H-pyrimido[1,2-b][1,2,4]triazine-7-carboxamide;
N-(4-chlorobenzyl)-2-(3-hydroxy-1-propynyl)-8-oxo-8H-pyriniido[1,2-b][1,2,4]-triazine-7-carboxamide;
N-(4-chlorobenzyl)-7-(4-morpholinylmethyl)-4-oxo-4H-quinolizine-3-carboxamide;
N-(4-chlorobenzyl)-7-(3-hydroxypropyl)4-oxo-4H-quinolizine-3-carboxamide;
N-(4-chlorobenzyl)-7-(3-hydroxy-1-propynyl)-4-oxo-4H-quinolizine-3-carboxamide;
N-(4-chlorobenzyl)-7-(3-hydroxy-1-propynyl)-4-oxo-4H-pyrido[1,2-a]pyrazine-3-carboxamide;
N-(4-chlorobenzyl)-7-(3-hydroxypropyl)-4-oxo-4H-pyrido[1,2-a]pyrazine-3-carboxamide;
N-(4-chlorobenzyl)-7-(4-morpholinylmethyl)-4-oxo-4H-pyrido[1,2-a]pyrazine-3-carboxamide;
N-(4-chlorobenzyl)-3-(4-morpholinylmethyl)-6-oxo-6H-pyrido[1,2-a]pyrimidine-7-carboxamide;
N-(4-chlorobenzyl)-6-(4-morpholinylmethyl)-4-oxo-4H-chromene-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxy-1-propynyl)-4-oxo-4H-chromene-3-carboxamide;
N-(4-chlorobenzyl)-6-(((3R)-3-hydroxypyrrolidinyl)methyl)-4-oxo4H-chromene-3-carboxamide;
N-(4-chlorobenzyl)-6,8-bis(4-morpholinylmethyl)-4-oxo4H-chromene-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxypropyl)-4-oxo-4H-chromene-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxypropyl)4-oxo-4H-pyrano[2,3-b]pyridine-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxy-1-propynyl)-4-oxo-4H-pyrano[2,3-b]pyridine-3-carboxamide;
N-(4-chlorobenzyl)-4-oxo-6-(tetrahydro-2H-pyran4-ylmethyl)4H-pyrano[2,3-b]-pyridine-3-carboxamide;
N-(4-chlorobenzyl)-6-(4-morpholinylmethyl)-4-oxo4H-pyrano[2,3-b]pyridine-3-carboxamide;
N-(4-chlorobenzyl)-6-(4-morpholinylmethyl)-4-oxo-4H-thiochromene-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxypropyl)-4-oxo-4H-thiopyrano[2,3-b]pyridine-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxy-1-propynyl)-4-oxo-4H-thiopyrano[2,3-b]pyridine-3-carboxamide;
N-(4-chlorobenzyl)-4-oxo-6-(tetrahydro-2H-pyran-4-ylmethyl)-4H-thiopyrano[2,3-b]-pyridine-3-carboxamide;
N-(4-chlorobenzyl)-6-(4-morpholinylmethyl)-4-oxo-4H-thiopyrano[2,3-b]pyridine-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxy-1-propynyl)4-oxo4H-1,2-benzoxazine-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxypropyl)-4-oxo-4H-1,2-benzoxazine-3-carboxamide;
N-(4-chlorobenzyl)-6-(4-morpholinylmethyl)-4-oxo4H-1,2-benzoxazine-3-carboxamide;
N-(4-chlorobenzyl)-4-oxo-6-(tetrahydro-2H-pyran4-ylmethyl)-4H-1,2-benzoxazine-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxy-1-propynyl)-4-oxo4H-1,2-benzthiazine-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxypropyl)4-oxo-4H-1,2-benzthiazine-3-carboxamide;
N-(4-chlorobenzyl)-6-(4-morpholinylmethyl)-4-oxo-4H-1,2-benzthiazine-3-carboxamide;
N-(4-chlorobenzyl)-4-oxo-6-(tetrahydro-2H-pyran-4-ylmethyl)-4H-1,2-benzthiazine-3-carboxamide;
N-(4-chlorobenzyl)-4-hydroxy-6-(3-hydroxy-1-propynyl)-1-methyl-1H-2,1-benzo-thiazine -3-carboxamide 2,2-dioxide;
N-(4-chlorobenzyl)-4-hydroxy-1-methyl-6-(4-morpholinylmethyl)-1H-2,1-benzo-thiazine -3-carboxamide 2,2-dioxide;
N-(4-chlorobenzyl)-4-methyl-7-(4-morpholinylmethyl)-4H-1,4-benzothiazine-2-carboxamide 1-oxide;
N-(4-chlorobenzyl)-1-methyl-6-(4-morpholinylmethyl)-1H-4,1,2-benzothiadiazine-3-carboxamide 4,4-dioxide;
N-(4-chlorobenzyl)-1-methyl-6-(4-morpholinylmethyl)-1H-thieno[2,3-e][1,3,4]-thiadiazine-3-carboxamide 4,4-dioxide;
N-(4-chlorobenzyl)-6-(4-morpholinylmethyl)-1H-thieno[2,3-e][1,3,4]thiadiazine-3-carboxamide 4,4-dioxide;
N-(4-chlorobenzyl)-6-(3-hydroxypropyl)-1H-thieno[2,3-e][1,3,4]thiadiazine-3-carboxamide 4,4-dioxide;
N-(4-chlorobenzyl)-6-(3-hydroxy-1-propynyl)-1H-thieno[2,3-e][1,3,4]thiadiazine-3-carboxamide 4,4-dioxide;
N-(4-chlorobenzyl)-6-(3-hydroxypropyl)-1-methyl-1H-thieno[2,3-e][1,3,4]-thiadiazine-3-carboxamide 4,4-dioxide;
N-(4-chlorobenzyl)-6-(3-hydroxy-1-propynyl)-1-methyl-1H-thieno[2,3-e][1,3,4]-thiadiazine-3-carboxamide 4,4-dioxide;
N-(4-chlorobenzyl)-6-(3-hydroxypropyl)-1,8-dimethyl-4,7-dioxo-1,4,7,8-tetrahydro [1,8] naphthyridine-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxy-1-propynyl)-1,8-dimethyl-4,7-dioxo-1,4,7,8-tetrahydro[1,8]naphthyridine-3-carboxamide;
N-(4-chlorobenzyl)-1,8-dimethyl-6-(4-morpholinylmethyl)-4,7-dioxo-1,4,7,8-tetrahydro[1,8]naphthyridine-3-carboxamide;
N-(4-chlorobenzyl)-7-(3-hydroxy-1-propynyl)-4-oxo-4H-pyrido[2,1-c][1,2,4]triazine-3-carboxamide;
N-(4-chlorobenzyl)-7-(3-hydroxypropyl)-4-oxo-4H-pyrido[2,1-c][1,2,4]triazine-3-carboxamide;
N-(4-chlorobenzyl)-7-(4-morpholinylmethyl)-4-oxo4H-pyrido[2,1-c][1,2,4]triazine-3-carboxamide;
N-(4-chlorobenzyl)-4-hydroxy-2-(4-morpholinylmethyl)-1-benzothiophene-5-carboxamide;
N-(4-chlorobenzyl)-4-hydroxy-2-(3-hydroxypropyl)-1-benzothiophene-5-carboxamide;
N-(4-chlorobenzyl)-2-(4-morpholinylmethyl)-5-oxo-5H-[1,3]thiazolo[3,2-a]-pyrimidine-6-carboxamide;
N-(4-chlorobenzyl)-5-hydroxy-2-(4-morpholinylmethyl)-7-oxo-7H-[1,3,4]thiadiazolo-[3,2-a]pyrimidine-6-carboxamide;
N-(4-chlorobenzyl)-4-methyl-2-(4-morpholinylmethyl)-7-oxo-4,7-dihydro[1,3]-thiazolo[5,4-b]pyridine-6-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxy-1-propynyl)-1-methyl-4-oxo-1,4-dihydrothieno[2,3-c]pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-6-(3-hydroxypropyl)-1-methyl-4-oxo-1,4-dihydrothieno[2,3-c]-pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-1-methyl-6-(4-morpholinylmethyl)-4-oxo-1,4-dihydrothieno[2,3-c]pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-6-(4-morpholinylmethyl)-4-oxo-1-phenyl-1,4-dihydrothieno[2,3-c]pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-1-methyl-4-oxo-6-(tetrahydro-2H-pyran-4-ylmethyl)-1,4-dihydro-thieno[2,3-c]pyridazine-3-carboxamide;
N-(4-chlorobenzyl)-4-hydroxy-6-(3-hydroxyprop-1-ynyl)-1-methyl-1H-thieno[2,3-c]-[1,2]thiazine-3-carboxamide 2,2-dioxide; and
pharmaceutically acceptable salts thereof.
Representative examples of the synthesis of compounds falling within the scope of formulas W1-W22 are as follows.
The following Charts A-BX describe the preparation of the compounds of the present invention. All of the starting materials are prepared by procedures described in these charts or by procedures analogous thereto, which would be well known to one of ordinary skill in organic chemistry. All of the final compounds of the present invention are prepared by procedures described in these charts or by procedures analogous thereto, which would be well known to one of ordinary skill in organic chemistry. All of the variables used in the charts are as defined below or as in the claims.
W1.1. 5-Hydroxy-2-oxo-2H-chromene-6-carboxamides. The preparation of specific examples of heterocycle W1.1 is described in Chart A. Methyl 3,5-dihydroxy-2-oxo-2H-chromene-6-carboxylate A.1 (J. Org. Chem. 1960, 25, 1817) is saponified to afford the corresponding carboxylic acid which is then coupled with a benzylamine (e.g. 4-chlorobenzylamine) mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to provide amides of the general formula A.2. Treatment of A.2 with triflic anhydride provides the enol triflate A.3. Sonogashira coupling of the enol triflate with an electron-rich acetylene (e.g. propargyl alcohol) in either diethylamine or in a mixture of DMF and triethylamine provides alkynyl-substituted derivatives of the general formula A.4. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives of the formula A.5. 
Specific examples of heterocycle W 1.1 in which G=CH2NR1R2 may be prepared by Chart B and C. Palladium catalyzed carbonylation of aryl triflate A.3 in the presence of tributyltin hydride provides the corresponding aldehyde B.1. Reductive amination with a primary or secondary amine (e.g. morpholine) and sodium cyanoborohydride affords derivatives of the formula B.2. Alternatively as described in Chart C, chloride displacement of 3,8-bis-chloromethyl-5-hydroxy-4-methyl-2-oxo-2H-chromene-6-carboxylate C.1 (J. Indian Chem. Soc. 1961, 38, 975) with a primary or secondary amine (e.g. morpholine) provides a bis-aminomethyl derivative C.2. the resulting ester is then saponified to afford the corresponding carboxylic acid which is then coupled with a benzylamine mediated by 1,1xe2x80x2-carbonyldiimidazole(or other suitable carboxylic acid activating agent) to provide amides of the general formula C.3. 
W2. 5-Hydroxy-2-oxo-1,2-dihydro-6-quinolinecarboxamides. The preparation of representative examples of heterocycle W2 is described in Chart D. 1,2,5-Trimethyl-6-oxo-1,6-dihydro-3-pyridinecarboxylic acid D.1 is converted to the corresponding methyl ester D.2 by treatment with diazomethane. This ester is then reacted with methyl methoxymethyleneacetoacetate and sodium methoxide to form the dihydroquinolone D.3 (J. Chem. Soc. Perkin 1 1979, 686). Amide formation is accomplished by treatment with neat 4-chlorobenzylamine at elevated temperature to give D.4. Oxidation of the allylic methyl group with selenium dioxide gives the allylic aldehyde D.5 which is converted to the terminal alkyne D.6 by treatment with the modified Wittig reagent, diethyl diazomethylphosphonate. Deprotonation of the alkyne with excess methylmagnesium bromide and trapping of the anion with an aldehyde (e.g. formaldehyde) affords the alkynyl-substituted derivatives of the formula D.7. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives D.8. 
Alternatively, representative examples of heterocycle W2 wherein G=CH2NR1R2 are prepared as described in Chart E. Bromination of the allylic methyl group of D.4 with bromine and AIBN provides the allylic bromide E.1 which can be displaced by amines such as morpholine to form the desired aminomethyl analogs such as E.2. 
W3.1. 4-Oxo-1,4-dihydro[1,7]naphthyridine-3-carboxamides. The preparation of representative examples of heterocycle W3.1 is described in Chart F. Condensation of 3-aminopyridine-N-oxide F.1 with diethyl ethoxymethylenemalonate followed by cyclization provides 1,7-naphthyridine-3-carboxylate F.2 (J. Org. Chem. 1954, 2008). Condensation of the resulting ester with 4-chlorobenzylamine at elevated temperatures provides the corresponding benzyl amide F.3. Reduction of the N-oxide followed by treatment with POBr3 affords 6-bromo-1,7-naphthyridine F.4. Alkylation with iodomethane in the presence of a suitable base provides compound F.5. Sonogashira coupling of F.5 with an electron-rich acetylene (e.g. propargyl alcohol) affords the alkynyl derivatives such as F.6. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives such as F.7. 
Specific examples of heterocycle W3.1 in which R6=OCH2CH3 are prepared as described in Chart G. 3-Amino-6-bromo-2-ethoxypyridine G.1 is condensed with diethyl ethoxymethylenemalonate, and the resulting enamine is cyclized thermally to provide naphthyridine ester G.2. Saponification of the ester followed by coupling of the resulting carboxylic acid with a benzylamine (e.g. 4-chlorobenzylamine) mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) provides amides of the general formula G.3. Alkylation of G.3 with iodomethane in the presence of a suitable base affords compounds of the formula G.4. Sonogashira coupling of G.4 with an electron-rich acetylene (e.g. propargyl alcohol) provides alkynyl-derivatives of the formula G.5. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives of the formula G.6. 
Specific examples of heterocycle W3.1 in which G=CH2NR1R2 are prepared as described in Chart H. The aryl bromides prepared above in Charts F and G (F.5 and G.4) undergo palladium catalyzed carbonylation in the presence of tributyltin hydride to give the corresponding aldehydes of the formula H.1. Reductive amination with a primary or secondary amine (e.g. morpholine) and sodium cyanoborohydride affords derivatives of the formula H.2. 
As shown in Chart BT, desired 4-oxo-1,4-dihydro[1,7]naphthyridines are prepared from 2-chloro-6-methylpyridin-3-amine (BT.1, available by the method of B. E. Tomczuk et. al. J. Med. Chem., 1991, 34, 2993-3006). Compound BT.2 is obtained by heating BT.1 in diethyl ethoxymethylenemalonate to 140xc2x0 C. Cyclization of BT.2 under thermal conditions in a high-boiling solvent such as diphenyl ether or under acid conditions such as by using PPA or Eatons reagent gives BT.3. The naphthyridine product BT.3 thus obtained is alkylated at N-1 with iodomethane (R=CH3) in DMF with K2CO3 at 25xc2x0 C. or with another suitable alkylating agent to give BT.4 (R=alkyl, substituted alkyl). Compound BT.4 is brominated for example with N-bromosuccinimide initiated by light in a suitable solvent such as dichloroethane to obtain the benzyl bromide BT.5 which is reacted with morpholine to obtain compound of the formula BT.6. Finally, ester BT.6 is reacted with 4-chlorobenzyl-amine, for example with trimethyl aluminum in dichloromethane or via another suitable amide forming route, to give the desired naphthyridines of the formula BT.7. Alternatively as shown in Chart BU, BT.6 is dechlorinated with catalytic palladium on carbon and hydrogen in methanol or another suitable reducing agent to give BU.1 which is treated with 4-chlorobenzylamine, for example with trimethylaluminum in dichloromethane or via another suitable amide forming route, to give desired products BU.2. 
As shown in Chart BV, additional examples of heterocycle W3.1 are prepared from 2,6-dimethyl-3-aminopyridine (BV.1). Compound BV.1 is condensed with diethyl ethoxymethylenemalonate to afford BV.2 which is then cyclized by heating in diphenyl ether to provide BV.3. The naphthyridine product BV.3 is alkylated at N-1 with iodomethane (R=CH3) in DMF with Na2CO3 or with another suitable alkylating agent to give BV.4 (R=alkyl, substituted alkyl). Compound BV.4 is brominated with N-bromosuccinimide initiated by light in a suitable solvent such as dichloroethane to obtain the intermediate bis-benzyl bromide which is reacted with morpholine to obtain compounds of the formula BV.5. Ester BV.5 is treated with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) at high temperature to afford the corresponding amides of the formula BV.6, or alternatively, the ester is saponified to afford the corresponding acid which is then coupled with a benzylamine mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to likewise provide amides of the formula BV.6. 
W3.2. 4-Oxo-1,4-dihydro[1,5]naphthyridine-3-carboxamides. Preparation of specific examples of heterocycle W3.2 follows established precedent for [1,5]naphthyridine ring synthesis (U.S. Pat. No. 3,225,055; Eur. J. Med. Chem. 1977, 12, 549; J. Chem. Soc., C. 1954, 2357-2361.), Chart I. The 3-aminopyridines I.1 (Y=tetrahydro-pyranylmethyl, prepared as described in Chart J) is condensed with diethyl ethoxy-methylenemalonate to afford the enamine of the formula I.2 (Y=tetrahydropyranyl-methyl). Similarly, the enamine I.2 (Y=chloro) is prepared as described in the literature (J. Heindl et al., Eur. J. Med. Chem. Chim. Ther. 1977, 12, 549-555). Thermal cyclization of these enamines in refluxing diphenyl ether provides the 1,4-dihydro[1,5]naphthyridine-3-esters I.3. The pyridone nitrogen is substituted by a group Z consisting of a substituted or unsubstituted, alkyl or cycloalkyl group by reaction of I.3 in the presence of a base and a species Z-leaving group (e.g. iodomethane) or by the reaction of I.3 with a species ZOH (e.g. methanol) under Mitsunobu conditions (Synthesis 1981, 1.) to afford compounds of the formula I.4.
The resulting ester is then treated with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) at high temperature or, alternatively, ester I.4 is saponified to afford the corresponding acid which is then coupled with a benzylamine mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) or, alternatively, ester I.4 may be treated with an above benzylamine and trimethylaluminum in an appropriate solvent to provide amides of the general formula I.5. 
I.1 (Y=4-tetrahydropyranylmethyl) is prepared according to Chart J. Wittig olefination between J.1 and 4-tetrahydropyranylphosphonium bromide (Bestmann, H. J.; Stransky, W.; Vostrowsky, O. Chem. Ber. 1979, 109, 1694-1700.) employing sodium hexamethyldisilazide as base provides the olefin J.3. Hydrogenation of J.3 catalyzed by palladium on carbon provides I.1 (Y=4-tetrahydropyranylmethyl). 
As described in Chart K for the case where Y=chloro (Chart I), the product I.4 (Y=chloro) is further derivatized. Sonogashira coupling of I.4 (Y=chloro) with an electron-rich acetylene (e.g. propargyl alcohol) catalyzed by PdCl2(PPh3)2 and copper(I) iodide either in diethylamine (Sonogashira, K.; Tohada, Y.; Hagihara, N. Tetrahedron Lett. 1975, 50, 4467.) or in a mixture of DMF and triethylamine (Fisher, M. J. et. al. J. Med. Chem. 1997, 40, 2085.) provides the corresponding alkynyl derivatives of formula K.1 (Z=CH2OH). The resulting ester is then treated with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) and trimethylaluminum in an appropriate solvent to provide amides of the general formula K.2. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives of formula K.3 (Z=CH2OH). 
Specific examples of heterocycle W3.2 where G=morpholinylmethyl are prepared as described in Chart L. Reduction of aldehyde L.1 with sodium borohydride followed by reduction of the nitro group via catalytic hydrogenation over platinum affords the amine L.2. Methylation of L.2 by sequential reaction with formic acetic anhydride and borane methyl sulfide complex provides L.3 which is condensed with diethyl ethoxymethylenemalonate to provide the corresponding enamine L.4. Acetylation of L.4 with acetic anhydride affords L.5 which is then cyclized thermally to prepare naphthyridine L.6. Treatment of the resulting ester with a benzylamine (e.g. 4-chlorobenzylamine) at high temperature affords carboxamides of the general formula L.7 with concurrent cleavage of the acetate. The resulting alcohol is treated with methanesulfonyl chloride followed by a primary or secondary amine (e.g. morpholine) to afford compounds of the formula L.8. 
W3.3. 5-Oxo-5,8-dihydropyrido[2,3-c]pyridazine-6-carboxamides. Preparation of specific examples of heterocycle W3.3 follows an established precedent for pyrido[2,3-c]pyridazine ring synthesis (G. Heinisch Arch. Pharm. 1990, 323, 207 -210.), Chart M. 2-Chloro-5-methylnicotinonitrile M.1 (Chem. Ber. 1964, 97, 3349) is heated with ethyl 3-ethylaminopropionate in the presence of a base (e.g. sodium bicarbonate) to afford pyridylamine M.2. Compound M.2 cyclizes to afford the bicycle M.3 upon treatment with sodium ethoxide which upon acid hydrolysis affords the pyridopyridazine M.4. Allylic bromination of M.4 employing conditions such as N-bromosuccinimide and AIBN provides the alkylhalide M.5 which is then displaced with a primary or secondary amine (e.g. morpholine) to afford a compound such as M.6. The resulting ester M.6 is then treated with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) at high temperature to afford the corresponding amides of the general formula M.7 or ester M.6 is saponified to afford the corresponding acid which is then coupled with a benzylamine mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to provide amides of the general formula M.7. 
W3.4. 8-Oxo-5,8-dihydropyrido[3,2-d]pyrimidine-7-carboxamide. Preparation of specific examples of heterocycle W3.4 follows an established literature precedent described in Chart N (U.S. Pat. No. 3,320,257 and J. Chem. Soc. C. 1967, 1745.). Heteroarylamine N.1 is condensed with diethyl ethoxymethylenemalonate to afford the enamine N.2. Cyclization of N.2 is effected by heating the enamine in diethylphthalate to provide bicycle N.3. The resulting ester N.3 is then saponified to afford the corresponding carboxylic acid N.4 which is then coupled with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to provide amides of the general formula N.5. The pyridone nitrogen is then substituted by a group Z consisting of a substituted or unsubstituted, alkyl or cycloalkyl group by reaction of N.5 in the presence of a base and a species Z-leaving group (e.g. iodomethane) or by the reaction of N.5 with a species ZOH (e.g. methanol) under Mitsunobu conditions (Synthesis 1981, 1.) to afford compounds of the formula N.6. Sonogashira coupling of N.6 with an electron-rich acetylene (e.g. propargyl alcohol) catalyzed by PdCl2(PPh3)2 and copper(I) iodide either in diethylamine (Sonogashira, K.; Tohada, Y.; Hagihara, N. Tetrahedron Lett. 1975, 50, 4467.) or in a mixture of DMF and triethylamine (Fisher, M. J. et. al. J. Med. Chem. 1997, 40, 2085.) provides the corresponding alkynyl derivatives of formula N.7 (Z=CH2OH). Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives of formula N.8 (Z=CH2OH). 
Alternatively, derivatives where G is specified as C1-4alkyl substituted by NR1R2 (e. g. 4-morpholinomethyl) are prepared from N.5 as described in Chart O. Compounds of the formula N.5 undergo palladium catalyzed carbon monoxide insertion and trapping with methanol to afford methyl esters of the formula O.1. The resulting esters are reduced with lithium aluminum hydride or other suitable reducing agent to provide the corresponding alcohols of the formula O.2. Alkylation of the pyridone nitrogen is accomplished as described above to afford compounds of the formula O.3. Activation of the alcohol as the mesylate by reaction with methanesulfonyl chloride in the presence of an amine base (e.g. collidine) followed by displacement with a primary or secondary amine (HNR1R2 such as morpholine) provides compounds of the formula O.4. 
W4.1. 4-Oxo-1,4-dihydropyrido[2,3-c]pyridazine-3-carboxamides. Preparation of specific examples of heterocycle W4. 1 follows an established literature precedent described in Chart P-Q (J. Heterocyclic Chem. 197, 24, 55.; Chem. Pharm. Bull. 1990, 38, 3211.; and Chem. Pharm. Bull. 1990, 38, 3359.). As described in Chart P. diazotization of xcex2-ketoesters P.1 (prepared as described in Chart S, where Y=4-morpholiylmethyl; Chart T, where Y=4-tetrahydropyranylmethyl; and Chart U. where Y=iodo) with tosyl azide. Reductive cyclization of P.2 with triphenyphosphine affords the pyridopyridazine P.3. The ring nitrogen atom of compound P.3 may then be optionally substituted by a group R inclusive to the group R7 consisting of a substituted or unsubstituted, alkyl or cycloalkyl group by reaction of P.3 in the presence of a base and a species R-leaving group (e.g. iodomethane) or by the reaction of P.3 with a species ZOH (e.g. methanol) under Mitsunobu conditions (Synthesis 1981, 1.) to afford compounds of the formula P.4. Esters P.3 or P.4 are then treated with a benzylamine (e.g. 4chlorobenzylamine, 4-bromobenzyladmine, or 4-fluorobenzylamine) at high temperature to afford the corresponding amides of the general formula P.5, or alternatively, the ester is saponified to afford the corresponding acid which is then coupled with a benzylamine mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to likewise provide amides of the general formula P.5. 
In another aspect, specific examples of heterocycle W4.1 in which R7=aryl or het are prepared as described in Chart Q. Treatment of compounds of the formula P.1 with an aryl- or heteroaryldiazonium chloride affords the hydrazone Q.1. Hydrazone Q.1 cyclizes to afford the pyridopyridazine Q.2 upon treatment with an appropriate base (e.g. potassium carbonate). The resulting ester may be transformed to the corresponding carboxamides of the general formula Q.3 in a similar fashion to that described in Chart P. 
As specified in Chart P and Chart Q, when Y=iodo, intermediates P.5 or Q.3 may be further elaborated to provide specific examples of heterocycle W4.1 where G=3-hydroxypropyl or 3-hydroxy-1-propynyl as described in Chart R. Intermediates P.5 and Q.3 undergo Sonogashira coupling with an electron-rich acetylene (e.g. propargyl alcohol, Z=CH2OH) catalyzed by PdCl2(PPh3)2 and copper(I) iodide either in diethylamine (Sonogashira, K.; Tohada, Y.; Hagihara, N. Tetrahedron Lett. 1975, 50, 4467.) or in a mixture of DMF and triethylamine (Fisher, M. J. et. al. J. Med. Chem. 1997, 40, 2085.) provides the corresponding alkynyl derivatives of formula R.1 (Z=CH2OH). Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives of formula R.2 (Z=CH2OH). 
P.1 (Y=morpholinylmethyl) is prepared according to Chart S. Reductive amination of 5-bromo-6-chloronicotinaldehyde S.1 (U.S. Pat. No. 4,317,913) with morpholine, acetic acid, and sodium triacetoxyborohydride provides the benzylmorpholine S.2. Metal-halogen exchange between n-butyllithium and S.2 at xe2x88x9270xc2x0 C. in tetrahydrofuran followed by addition of the resulting aryl lithium to N-methoxy-N-methylacetamide yields the methylketone S.3. Treatment of S.3 with a base such as sodium hydride in the presence diethylcarbonate affords the xcex2-ketoester P.1 (Y=morpholinylmethyl) which may then be employed as in Chart P. 
P.1 (Y=4-tetrahydropyranylmethyl) is prepared according to Chart T. Wittig olefination between S.1 and 4-tetrahydropyranylphosphonium bromide (Bestmann, H. J.; Stransky, W.; Vostrowsky, O. Chem. Ber. 1979, 109, 1694-1700.) employing sodium hexamethyldisilazide as base provides the olefin T.1. Metal-halogen exchange between n-butyllithium and T.1 at xe2x88x9270xc2x0 C. in tetrahydrofuran followed by addition of the resulting heteroaryl lithium to carbon dioxide yields the carboxylic acid T.2. Saturation of the olefin by hydrogenation of T.2 employing palladium on carbon as catalyst affords T.3. Conversion of T.3 to its corresponding imidazolide with 1,1xe2x80x2-carbonyldiimidazole followed by treatment with the trimethylsilyl ester of ethyl hydrogen malonate in the presence of DBU (Wang, X.; Monte, W. T.; Napier J. J.; Ghannam, A. Tetrahedron Lett. 1994, 35, 9323-9326) provides xcex2-ketoester P.1 (Y=4-tetrahydropyranylmethyl) which may be employed as in Chart P. 
P.1 (W=iodo) is prepared according to Chart U. Conversion of 2-chloro-5-iodonicotinic acid U.1 (J. Chem. Eng. Data 1976, 21, 246.) to its corresponding imidazolide with 1,1xe2x80x2-carbonyldiimidazole followed by treatment with the trimethylsilyl ester of ethyl hydrogen malonate in the presence of DBU (Wang, X.; Monte, W. T.; Napier J. J.; Ghannam, A. Tetrahedron Lett. 1994, 35, 9323-9326) provides xcex2-ketoester P.1 (W=iodo) which may be employed as in Chart P. 
W4.2. 4-Oxo-1,4-dihydropyrido[3,4-c]pyridazine-3-carboxamides. Specific examples of heterocycle W4.2 where G=3-hydroxypropyl or 3-hydroxy-1-propynyl are prepared as described in Chart V. Treatment of V.1 with bromine and aqueous sodium hydroxide according to the procedure of Moss et. al. (Tetrahedron Letters 1993, 34, 6225-6228) affords the amino acid V.2. This material is then treated with di-t-butyldicarbonate in an appropriate solvent such as THF, MeOH, DMF or mixtures thereof with a base such as triethylamine or sodium bicarbonate to give the t-butylcarbamate V.3. Treatment of V.3 with carbonyldiimidazole or another suitable acid-activating agent followed by the addition of ethyl trimethylsilylmalonate and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in a suitable solvent such as acetonitrile provides the ester V.4. Removal of the t-butylcarbamate protecting group by well known methods (trifluoroacetic acid in dichloromethane or hydrochloric acid in a solvent such as dioxane, ether or THF) affords the aniline V.5. Treatment of V.5 with sodium nitrite in aqueous acid yields the cyclized intermediate V.6. Heating this material in the presence of 4-chlorobenzylamine affords the amide V.7. Treatment with bromine in carbon tetrachloride provides the bromide V.8 which can then be coupled to an electron-rich acetylene (e.g. propargyl alcohol, Z=CH2OH) catalyzed by PdCl2(PPh3)2 and copper(I) iodide either in diethylamine (Sonogashira, K.; Tohada, Y.; Hagihara, N. Tetrahedron Lett. 1975, 50, 4467.) or in a mixture of DMF and triethylamine (Fisher, M. J. et. al. J. Med. Chem. 1997, 40, 2085.) to provide the corresponding alkynyl derivatives of formula V.9 (Z=CH2OH). The nitrogen can then be alkylated with alkyl halides (e.g. iodomethane) and a suitable base by well known methods to give V.10. Saturation of the alkyne precursor V.9 by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives of formula V.11 (Z=CH2OH). Alkylation of nitrogen as described above provides compounds of the formula V.12. 
Specific examples of heterocycle W4.2 where G=CH2NR1R2 are prepared as described in Chart X. Bromide V.8 is formylated with PdCl2(PPh3)2, carbon monoxide, and sodium formate in DMF to afford carboxaldehyde X.1 according to the procedure of Okano (Bull. Chem. Soc. Jpn. 1994, 67, 2329.). This material is then subjected to reductive amination conditions with a primary or secondary amine (e.g. morpholine) to provide compounds of the formula X.2 which are then alkylated at nitrogen as described above to yield X.3. 
W6.1. 4-Oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxamides. Specific examples of heterocycle W6.1 are prepared as described in Chart Y. Iodination of 2-amino-pyridine Y.1 with iodine in periodic and acetic acids provides 2-amino-5-iodopyridine Y.2 Condensation of Y.2 with diethyl ethoxymethylenemalonate followed by thermal cyclization in refluxing diphenyl ether affords the pyridopyrimidine Y.3. Treatment of Y.3 with 4-chlorobenzylamine and trimethylaluminum provides Y.4. Sonogashira coupling of Y.4 to an electron-rich acetylene (e.g. propargyl alcohol) in a mixture of DMF and triethylamine at elevated temperature provides the alkynyl-substituted analogs Y.5. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords the corresponding alkyl derivatives Y.6. 
In another aspect, specific examples of heterocycle W6. 1 in which G=CH2NR1R2 are prepared as described in Chart Z. Palladium mediated carbonylation of aryl iodide Z.4 in the presence of tributyltin hydride provides the aldehyde Z.1. Reductive amination with a primary or secondary amine (e.g. morpholine) and sodium cyano-borohydride provides derivatives of the formula Z.2. 
A specific example of heterocycle W6.1 in which R8=OH is prepared as described in Chart AA. Sonogashira coupling of iodopyridine Y.2 with 2-(2-propynyloxy)-tetrahydro-2H-pyran affords the alkyne AA.1 which is condensed with diethyl 2-(((4-chlorobenzyl)amino)carbonyl)malonate (prepared by the reaction of 4-chlorobenzyl-amine with triethyl methanetricarboxylate) to afford the pyridopyrimidine AA.2. Deprotection of the tetrahydropyanyl protecting group in acidic methanol provides compounds of the formula AA.3. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives of formula AA.4. 
W6.2. 4-Oxo-4H-pyrazino[1,2-a]pyrimidine-3-carboxamides. The preparation of specific examples to heterocycle W6.2 in which G=3-hydroxypropyl or 3-hydroxy-1-propynyl is described in Chart AB. 5-Bromopyrazine AB.1, is condensed with diethyl ethoxymethylenemalonate, and the resulting enamine is cyclized thermally in refluxing diphenyl ether to afford the pyrazinopyrimidine ester AB.2. The resulting ester is then reacted with a benzylamine (e.g. 4-chlorobenzylamine) at high temperature to give carboxamides of the formula AB.3. Sonogashira coupling between AB.3 and an electron-rich acetylene (e.g. propargyl alcohol) provides alkynyl derivatives of the formula AB.4. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords the corresponding alkyl derivatives AB.5. 
Specific examples of heterocycle W6.2 in which G=CH2NR1R2 are prepared as described in Chart AC. Methyl 5-amino-2-pyrazinecarboxylate AC.1 (Helv. Chim. Acta. 1964, 47, 873) is reduced by treatment with sodium borohydride in methanol/water (U.S. Pat. No. 4,267,327) to afford alcohol AC.2. Condensation of AC.2 with diethyl ethoxymethylenemalonate, followed by acylation of the free alcohol with acetic anhydride in acetic acid provides AC.3. Thermal cyclization of AC.3 affords the pyrazinopyriridine ester AC.4. The resulting ester AC.4 is then reacted with a benzylamine (e.g. 4-chlorobenzylamine) at high temperature to provide carboxamides of the general formula AC.5 with concurrent cleavage of the acetate. Activation of the hydroxy group as the corresponding mesylate by reaction with methanesulfonyl chloride in the presence of a suitable base followed by nucleophilic displacement by a primary or secondary amine (e.g. morpholine) affords derivatives such as AC.6. 
W6.3. 4-Oxo-4H-pyrimido[1,2-b]pyridazine-3-carboxamide. Preparation of specific examples of heterocycle W6.3 follows an established literature precedent described in Chart AD (J. Org. Chem. 1971, 36, 2457 and U.S. Pat. No. 4,231,928). Heterocyclic amine AD.1 (Aust. J. Chem. 1997, 50, 61-67.) is condensed with diethyl ethoxy-methylenemalonate to afford enamine AD.2. Cyclization of the resulting enamine by heating in polyphoric acid (PPA) provides pyrimidopyridazine AD.3. The resulting ester AD.3 is then saponified to afford the corresponding carboxylic acid AD.4 which is then coupled with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to provide amides of the general formula AD.5. To prepare derivatives where G=3-hydroxypropyl or 3-hydroxy-1-propynyl, intermediate AD.5 may be further elaborated by Sonogashira coupling with an electron-rich acetylene (e.g. propargyl alcohol, Z=CH2OH) catalyzed by PdCl2(PPh3)2 and copper(I) iodide either in diethylamine (Sonogashira, K.; Tohada, Y.; Hagihara, N. Tetrahedron Lett. 1975, 50, 4467.) or in a mixture of DMF and triethylamine (Fisher, M. J. et. al. J. Med. Chem. 1997, 40, 2085.) provides the corresponding alkynyl derivatives of formula AD.6 (Z=CH2OH). Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives of formula AD.7 (Z=CH2OH). 
Specific examples of heterocycle W6.3 where G=4-morpholinomethyl or 4-tetrahydropyranylmethyl are prepared from intermediate AD.5 as described in Chart AE. Compounds of the formula AD.5 are transformed to the corresponding aldehyde AE.1 by reaction with carbon monoxide, tributyltin hydride and a palladium catalyst (e.g. palladium tetrakis-triphenylphosphine) (J. K. Stille J. Am. Chem. Soc. 1986, 108, 452-461.). Reductive amination of AE.1 with morpholine, acetic acid, and sodium triacetoxyborohydride provides the morpholinylmethyl derivatives of the formula AE.2 (Y=N). Alternatively, Wittig olefination between AE.1 and 4-tetrahydropyranylphosphonium bromide (Bestmann, H. J.; Stransky, W.; Vostrowsky, O. Chem. Ber. 1979, 109, 1694-1700.) employing sodium hexamethyldisilazide as base followed by hydrogenation catalyzed by palladium on carbon provides AE.2 (Y=CH). 
W6.4. 4-Oxo-4H-pyrimido[1,2-a]pyrimidine-3-carboxamide. Preparation of specific examples of heterocycle W6.4 follows an established literature precedent described in Chart AF (Aust. J. Chem. 1994, 47, 1263-1270.). Heterocyclic amine AF.1 (Heterocycles 1984, 22, 1195) is condensed with diethyl ethoxymethylenemalonate to afford enamine AF.2. Cyclization of the resulting enamine by flash vacuum pyrolysis or by heating in a high boiling solvent provides pyrimidopyrimidine AF.3. The resulting ester AF.3 is then saponified to afford the corresponding carboxylic acid AF.4 which is then coupled with a benzylamnine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to provide amides of the general formula AF.5. To prepare derivatives where G=3-hydroxypropyl or 3-hydroxy-1-propynyl, intermediate AF.5 may be further elaborated by Sonogashira coupling with an electron-rich acetylene (e.g. propargyl alcohol, Z=CH2OH) catalyzed by PdCl2(PPh3)2 and copper(I) iodide either in diethylamine (Sonogashira, K.; Tohada, Y.; Hagihara, N. Tetrahedron Lett. 1975, 50, 4467.) or in a mixture of DMF and triethylamine (Fisher, M. J. et. al. J. Med. Chem. 1997, 40, 2085.) provides the corresponding alkynyl derivatives of formula AF.6 (Z=CH2OH). Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives of formula AF.7 (Z=CH2OH). 
Specific examples of heterocycle W6.4 where G=4-morpholinomethyl or 4-tetreahydropyranylmethyl are prepared from intermediate AF.5 as described in Chart AG. Compounds of the formula AF.5 are transformed to the corresponding aldehydeAG.1 by reaction with carbon monoxide, tributyltin hydride and a palladium catalyst (e.g. palladium tetrakis-triphenylphosphine) (J. K. Stille J. Am. Chem. Soc. 1986, 108, 452-461.). Reductive amination of AG.1 with morpholine, acetic acid, and sodium triacetoxyborohydride provides the morpholinylmethyl derivatives of the formula AG.2 (Y=N). Alternatively, Wittig olefination between AG.1 and 4-tetrahydropyranylphosphonium bromide (Bestmann, H. J.; Stransky, W.; Vostrowsky, O. Chem. Ber. 1979, 109, 1694-1700.) employing sodium hexamethyldisilazide as base followed by hydrogenation catalyzed by palladium on carbon provides AG.2 (Y=CH). 
W6.5. 8-Oxo-8H-pyrimido[1,2-b][1,2,4]triazine-7-carboxamides. The preparation of specific examples of heterocycle W6.5. follows established precedent as described in Chart AH. The 1-amino-4-iodo pyrazine AH.1 (Jovanovic, M. V. Heterocycles, 1984, 22, 1195) is condensed with methyl 2-(((4-chlorobenzyl)amino)carbonyl)-3-methoxy-2-propenoate to afford pyrimidotriazine AH.2. For specific examples where G=CH2NR1R2, AH.2 is transmetallated with n-butyllithium and the resulting anion is reacted with dimethylformamide to afford the corresponding carboxaldehyde AH.3. The resulting aldehyde is then reacted under reductive amination conditions with a primary or secondary amine (e.g. morpholine) in the presence of acetic acid and sodium cyanoborohydride to afford examples such as AH.4. Alternatively for examples where G=3-hydroxypropyl or 3-hydroxy-1-propynyl, iodide AH.2 is coupled with an electron-rich acetylene (e.g. propargyl alcohol) through a modified Sonogashira coupling (Linstrumelle, G.; et. al, Tetrahedron Lett. 1993, 34, 6403) to afford compounds such as AH.5. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives such as AH.6. 
W7.1. 4-Oxo-4H-quinolizine-3-carboxamide. Specific examples of heterocycle W7.1 in which G=CH2NR1R2 are prepared as described in Chart AI. 2-Methyl-3-pyridinecarboxylate AI.1 is reduced with lithium aluminum hydride, and the resulting alcohol AI.2 is protected as its methoxymethyl (MOM) ether by treatment with chloromethylmethyl ether in the presence of a suitable base to afford ether AI.3. Deprotonation with n-butyllithium and trapping of the resulting anion with diethyl ethoxymethylenemalonate provides the malonate diester AI.4 (U.S. Pat. No. 4,698,349). Thermal cyclization of AI.4 in refluxing diphenyl ether affords the quinolizine AI.5. The resulting ester AI.5 is then treated with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) at high temperature to afford the corresponding amides of the general formula AI.6, or alternatively, the ester may be saponified to afford the corresponding acid which is then coupled with a benzylamine mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to likewise provide AI.6. Deprotection of the methoxymethyl ether affords the benzyl alcohol AI.7 which is then activated as its mesylate ester by reaction with methanesulfonyl chloride and suitable base. Subsequent nucleophilic displacement by a primary or secondary amine (e.g. morpholine) provides derivatives of the formula AI.8. 
Specific examples of heterocycle W7.1 in which G=3-hydroxypropyl or 3-hydroxy -1-propynyl are prepared as described in Chart AJ. Oxidation of benzyl alcohol AI.7 to under Swern oxidation conditions or other suitable oxidizing conditions affords the corresponding aldehyde AJ.1. Treatment of AJ.1 with the corresponding Wittig reagent diethyl diazomethylphosphonate provides the terminal alkyne AJ.2. Deprotonation of the terminal alkyne with excess methylmagnesium bromide and trapping of the resulting anion with an aldehyde (e.g. formaldehyde) gives alkynyl derivatives of the formula AJ.3. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords the corresponding alkyl derivatives of the formula AJ.4. 
W7.2. 4-Oxo-4H-pyrido[1,2-a]pyrazine-3-carboxamide. Representative examples of heterocycle W7.2 in which G=3-hydroxypropyl or 3-hydroxy-1-propynyl are prepared as described in Chart AK. Saponification of ethyl 7-cyano4-oxo-4H-pyrido[1,2-a]pyrazine carboxylate (AK.1, J. Chem. Soc. Perkin 1 1977, 789) with lithium hydroxide in methanol provides the corresponding carboxylic acid AK.2. Carboxylic acid AK.2 is then coupled with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to provide amides of the general formula AK.3. Reduction of the cyano functionality employing Raney nickel and sodium hypophosphite (J. Chem. Soc. 1962, 3961-3963.) in an acetic acid and water mixture provides the corresponding aldehyde AK.4. Treatment of the resulting aldehyde with the modified Wittig reagent diethyl diazomethylphosphonate affords the terminal alkyne AK.5. Deprotonation of the alkyne with excess methylmagnesium bromide and condensation with an aldehyde (e.g. formaldehyde) yields substituted alkynes of the general formula AK.6. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives of the formula AK.6. 
In another aspect, specific examples of heterocycle W7.2 in which G=morpholinyl-methyl are prepared as described in Chart AL. Reductive amination of AK.4 with a primary or secondary amine (e.g. morpholine) and sodium cyanoborohydride affords derivatives of the formula AL.1. 
W7.3. 6-Oxo-6H-pyrido[1,2-a]pyrimidine-7-carboxamide. The preparation of specific examples of heterocycle W7.3 follows established literature precedent for 2-pyridones (Li, Q.; et. al. J. Med. Chem. 1996, 39, 3070) as described in Chart AM. Acetamidine is condensed with dimethyl methoxymethylenemalonate to afford pyrimidine AM.1. The ester AM.1 is hydrolyzed, heated with thionyl chloride, and the resulting acid chloride is reacted with morpholine to provide the amide AM.2. The chloroamide is then reduced with lithium aluminum hydride to afford pyrimidine AM.3. The pyrimidine is then deprotonated with n-butyllithium and the resulting anion is condensed with methyl 2-(((4-chlorobenzyl)amino)carbonyl)-3-methoxy-2-propenoate and subsequently cyclized to afford pyridopyrimidines of the general formula AM.4. 
W8.1. 4-Oxo-4H-chromene-3-carboxamide. Specific examples of heterocycle W8.1 in which G=3-hydroxypropyl or 3-hydroxy-1-propynyl are prepared as described in Chart AN. 6-Bromochromone-3-carboxaldehyde AN.1 is oxidized to the carboxylic acid bromide AN.2 by a light-catalyzed oxidation with N-bromosuccinimide. The resulting acid bromide is then reacted with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) to provide amides of the general formula AN.3. Sonogashira coupling of the aryl bromide AN.3 with an electron-rich acetylene (e.g. propargyl alcohol, Z=CH2OH) provides the alkyne derivatives of the formula AN.4. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords the corresponding alkyl derivatives of the formula AN.5. 
In another example, derivatives of heterocycle W8.1 in which G=CH2NR1R2 are prepared as described in Chart AO. 6-Methyl-3-formylchoromone (AO.1, Z=H) is irradiated in the presence of N-bromosuccinimide. The resulting acylbromide is then treated with an benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) to provide an intermediate carboxamide which is treated with a primary or secondary amine (e.g. morpholine) to provide compounds of the formula AO.2 (Z=H). In the case where 6,8-dimethyl-3-formylchoromone (AO.1, Z=CH3) is employed the resulting product AO.2 (Z=morpholinylmethyl) is provided. 
W8.2. 4-Oxo4H-pyrano[2,3-b]pyridine-3-carboxamide. Preparation of specific examples of heterocycle W8.2 follows an established literature precedent described in Chart AP (Heterocycles 1993, 35, 93-97). 3-Pyridylcarboxylic acid AP.1 (J. Med. Chem. 1997, 40, 2674-2687) is converted to its corresponding imidazolide with 1,1xe2x80x2-carbonyldiimidazole and coupled with the lithium anion of tert-butyl acetate to afford xcex2-ketoester AP.2. Ring closure is effected by treating AP.2 with MeOCHxe2x95x90NMe2+ MeOSO3xe2x88x92 to afford ester AP.3. The resulting ester AP.3 is then hydrolyzed with trifluoroacetic acid to afford the corresponding carboxylic acid AP.4 which is then coupled with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to provide amides of the general formula AP.5. To prepare derivatives where G=3-hydroxypropyl or 3-hydroxy-1-propynyl, intermediate AP.5 may be further elaborated by Sonogashira coupling with an electron-rich acetylene (e.g. propargyl alcohol, Z=CH2OH) catalyzed by PdCl2(PPh3)2 and copper(I) iodide either in diethylamine (Sonogashira, K.; Tohada, Y.; Hagihara, N. Tetrahedron Lett. 1975, 50, 4467.) or in a mixture of DMF and triethylamine (Fisher, M. J. et. al. J. Med. Chem. 1997, 40, 2085.) provides the corresponding alkynyl derivatives of formula AP.6 (Z=CH2OH). Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives of formula AP.7 (Z=CH2OH). 
Specific examples of heterocycle W8.2 where G=4-morpholinomethyl or 4-tetreahydropyranylmethyl are prepared from intermediate AP.5 as described in Chart AQ. Compounds of the formula AP.5 are transformed to the corresponding aldehyde AQ.1 by reaction with carbon monoxide, tributyltin hydride and a palladium catalyst (e.g. palladium tetrakis-triphenylphosphine) (J. K. Stille J. Am. Chem. Soc. 1986, 108, 452-461.). Reductive amination of AQ.1 with morpholine, acetic acid, and sodium triacetoxyborohydride provides the morpholinylmethyl derivatives of the formula AQ.2 (Y=N). Alternatively, Wittig olefination between AQ.1 and 4-tetrahydropyranylphosphonium bromide (Bestmann, H. J.; Stransky, W.; Vostrowsky, O. Chem. Ber. 1979, 109, 1694-1700.) employing sodium hexamethyldisilazide as base followed by hydrogenation catalyzed by palladium on carbon provides AQ.2 Y=CH) 
W8.8. 4-Oxo-4H-thiochromene-3-carboxamide. Specific examples of heterocycle W8.8 in which G=morpholinylmethyl are prepared as described in Chart AR. Deprotonation of the 6-methyl-thiochroman-4-one AR.1 with LDA at low temperatures and subsequent treatment of the enolate with HMPA and methylcyanoformate (Mander, L. N.; Sethi, S. P. Tetrahedron. Lett. 1983, 24, 5425-5428) provides the xcex2-ketoester AR.2. Bromination alpha to the carbonyl using bromine in a mixture of diethyl ester and carbon tetrachloride affords bromide AR.3. Subsequent elimination is affected using lithium carbonate in DMF at 100xc2x0 C. to give the thiochromenone AR.4. Benzylic bromination (NBS, benzoyl peroxide, carbon tetrachloride) provides bromide AR.5, which is subsequently displaced with a primary or secondary amine (e.g. morpholine) to give AR.6. The resulting ester is then treated with a dimethyl-aluminumamide derived from trimethylaluminum and a benzylamine (e.g. 4-chloro-benzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) to afford amides of the formula AR.7. 
W8.9. 4-Oxo-4H-thiopyrano[2,3-b]pyridine-3-carboxamides. Preparation of specific examples of heterocycle W8.9 follows an established literature precedent described in Heterocycles 1993, 35, 93-97. and is analogous to that described above for heterocycle W8.2. employing 2-thiol-5-iodo-3-pyridylcarboxylic acid in the place of AO.1 prepared by N-iodosuccinimide iodination (J. Med. Chem. 1997, 40, 2674-2687) of 2-thiol-3-pyridylcarboxylic acid (J. Heterocyclic Chem. 1985, 22, 1353.).
Alternatively, derivatives of heterocycle W8.9 where G=CH2NR1R2 are prepared as described in Chart AS. Activation of carboxylic acid AS.1 (Heterocycles, 1994, 38, 333) with 1,1xe2x80x2-carbonyldiimidazole or another suitable acid-activating agent followed by the addition of the lithium salt of tert-butyl acetate results in compound AS.2. Reaction of AS.2 under McCombie cyclization conditions using MeOCHxe2x95x90NMe2+MeOSO3xe2x88x92 (Heterocycles, 1993, 35, 93) affords thiopyranopyridin-4-one AS.3. Bromination at the benzylic position using N-bromosuccinimide and benzoylperoxide provides bromide AS.4, which undergoes nucleophilic displaced by a primary or secondary amine (e.g. morpholine) to afford AS.5. Deprotection of the tert-butylester provides acid AS.6, which is then coupled with 4-chlorobenzylamine via well known methods to afford carboxamide derivatives of the formula AS.7. 
W10.1. 4-Hydroxy-2H-1,2-benzoxazine-3-carboxamides. Preparation of specific examples of heterocycle W10.1 follows an established literature precedent described in Chart AT (G. S. Shchegoleva Khim. Geterotsikl. Soedin., Sb. 1970, 2, 278-281; Chem. Abst. 1972, 76, 140675.). Treatment of xcex2-ketoesters of the formula AT.1 (prepared as described in Chart AV, Y=4-morpholinylmethyl; Chart AW, Y=iodo and 3-hydroxypropyl; Chart AX, Y=4-tetrahydropyranylmethyl) with sodium nitrite in acetic acid (J. Chem. Soc. 1925, 579) affords oximes of the formula AT.2. Upon heating, oximes AT.2 cyclize to afford compounds of the formula AT.3. The resulting ester AT.3 is then reacted with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) at high temperature or alternatively the ester is saponified to afford the corresponding carboxylic acid which is then coupled with a benzylamine mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to provide amides of the general formula AT.4. In the case where Y=iodo, the resulting amide may be further elaborated as described in Chart AU by Sonogashira coupling with an electron-rich acetylene (e.g. propargyl alcohol, Z=CH2OH) catalyzed by PdCl2(PPh3)2 and copper(I) iodide either in diethylamine (Sonogashira, K.; Tohada, Y.; Hagihara, N. Tetrahedron Lett. 1975, 50, 4467.) or in a mixture of DMF and triethylamine (Fisher, M. J. et. al. J. Med. Chem. 1997, 40, 2085.) to provide the corresponding alkynyl derivatives of formula AU.1 (Z=CH2OH). 
AT.1 (W=morpholinylmethyl) is prepared according to Chart AV. Reductive amination of 3-bromo4-fluorobenzaldehyde (AV.1) with morpholine, acetic acid, and sodium triacetoxyborohydride provides the benzylmorpholine AV.2. Metal-halogen exchange between n-butyllithium and AV.2 at xe2x88x9270xc2x0 C. in tetrahydrofuran followed by addition of the resulting aryl lithium to N-methoxy-N-methylacetamide yields the methylketone AV.3. Treatment of AV.3 with a base such as sodium hydride in the presence diethylcarbonate affords the xcex2-ketoester AT.1 (W=morpholinylmethyl) which may then be employed as in Chart AT. 
AT.1 (W=iodo) is prepared according to Chart AW. Conversion of 2-fluoro-5-iodobenzoic acid AW.1 (Blackburn, B. K. et. al. J. Med. Chem. 1997, 40, 717-729) to its corresponding imidazolide with 1,1xe2x80x2-carbonyldiimidazole followed by treatment with the trimethylsilyl ester of ethyl hydrogen malonate in the presence of DBU (Wang, X.; Monte, W. T.; Napier J. J.; Ghannam, A. Tetrahedron Lett. 1994, 35, 9323-9326) provides xcex2-ketoester AT.1 (W=iodo) which may be employed as in Chart AT.
AT.1 (W=3-hydroxypropyl) is prepared according to Chart AW. Sonogashira coupling of AT.1 (W=iodo) with propargyl alcohol as described above provides the corresponding alkynyl derivatives AW.2. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords AT.1 (W=3-hydroxypropyl) which may be employed as in Chart AT. 
AT.1 (W=4-tetrahydropyranylmethyl) is prepared according to Chart AX. Wittig olefination between 3-bromo-4-fluorobenzaldehyde (AV.1) and 4-tetrahydropyranylphosphonium bromide (Bestmann, H. J.; Stransky, W.; Vostrowsky, O. Chem. Ber. 1979, 109, 1694-1700.) employing sodium hexamethyldisilazide as base provides the olefin AX.1. Metal-halogen exchange between n-butyllithium and AX.1 at xe2x88x9270xc2x0 C. in tetrahydrofuran followed by addition of the resulting aryl lithium to carbon dioxide yields the carboxylic acid AX.2. Saturation of the olefin by hydrogenation of AX.2 employing palladium on carbon as catalyst affords AX.3. Conversion of AX.3 to its corresponding imidazolide with 1,1xe2x80x2-carbonyldiimidazole followed by treatment with the trimethylsilyl ester of ethyl hydrogen malonate in the presence of DBU (Wang, X.; Monte, W. T.; Napier J. J.; Ghannam, A. Tetrahedron Lett. 1994, 35, 9323-9326) provides 3-ketoester AT.1 (Y=4-tetrahydropyranymethyl) which may be employed as in Chart AT. 
W10.2. 4-Hydroxy-2H-1,2-benzothiazine-3-carboxamides. Preparation of specific examples of heterocycle W10.2 follows an established literature precedent described in Chart AY (S. Jones J. Chem. Soc., Chem. Commun. 1990, 497498.). 4,4xe2x80x2-Diiodo-2,2xe2x80x2-dicarboxydiphenyldisulfide AY.1 (N. D. Heindel J. Heterocyclic Chem. 1970, 1007) is reduced with triphenylphosphine (Coll. Czech. Chem. Commun. 1988, 53, 341-360.) to afford thiol AY.2 which is then S-alkylated with iodomethane in the presence of sodium hydroxide (Coll. Czech. Chem. Commun. 1976, 41, 3384.) to afford AY.3. Conversion of AY.3 to its corresponding imidazolide with 1,1xe2x80x2-carbonyldiimidazole followed by treatment with the trimethylsilyl ester of ethyl hydrogen malonate in the presence of DBU (Wang, X.; Monte, W. T.; Napier J. J.; Ghannam, A. Tetrahedron Lett. 1994, 35, 9323-9326) provides xcex2-ketoester AY.4. Treatment of AY.4 with sodium nitrite in acetic acid affords the corresponding oxime AY.5 which is then O-tosylated with 4toluenesulfonylchloride and an amine base to provide AY.6. Upon heating AY.6 in toluene with p-toluenesulfonic acid, ring cyclization occurs to afford ester AY.7. The resulting ester AY.7 is then saponified to afford the corresponding carboxylic acid AY.8 which is then coupled with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to provide amides of the general formula AY.9. Sonogashira coupling of AY.9 with propargyl alcohol catalyzed by PdCl2(PPh3)2 and copper(I) iodide either in diethylamine (Sonogashira, K.; Tohada, Y.; Hagihara, N. Tetrahedron Lett. 1975, 50, 4467.) or in a mixture of DMF and triethylamine (Fisher, M. J. et. al. J. Med. Chem. 1997, 40, 2085.) provides the corresponding alkynyl derivatives of formula AY.10. 
Examples of heterocycle W10.2 where G=4-morpholinylmethyl are prepared as described in Chart AZ. Carboxamide AY.9 is treated with carbon monoxide, tributyltin hydride, and a palladium catalyst (e.g. palladium tetrakis-triphenyl-phosphine) (J. K. Stille J. Am. Chem. Soc. 1986, 108, 452-461.) to afford the corresponding aldehyde AZ.1. Reductive amination of AZ.1 with morpholine, acetic acid, and sodium triacetoxyborohydride provides the morpholinylmethyl derivatives of the formula AZ.2. 
W13.4. 4-Hydroxy-1H-2,1-benzothiazine-3-carboxamide 2,2-dioxides. The preparation of specific examples of heterocycle W13.4 is described in Chart BA. For compounds in which G=CH2NR1R2, 6-bromo-3,4-dihydro-1H-2,1-benzothiazin-4-one 2,2-dioxide BA.1 (B. Loev, K. M. Snader J. Heterocyclic Chem., 1967, 4, 403) is treated with palladium tetrakistriphenylphosphine and tributyltin hydride under an atmosphere of carbon monoxide (Baillageon, V. P., Stille J. K., J. Am. Chem. Soc. 1983, 105, 7175) to afford aldehyde BA.2. Reductive amination of BA.2 with a primary or secondary amine (e.g. morpholine) and sodium triacetoxyborohydride affords compounds such as BA.3. Treatment of BA.3 with a benzylisocyanate (e.g. 4-chlorobenzyl isocyanate prepared as described by H. Stark, et. al. J. Med. Chem. 1996, 39, 1157-1163.) affords the corresponding carboxamide BA.4. 
Additional examples of heterocycle W13.4 in which G 3-hydroxypropyl or 3-hydroxy-1-propynyl are prepared as described in Chart BW. 5-Iodoanthranilic acid methyl ester (BW.1) is converted to the corresponding sulfonamide with methane-sulfonyl chloride to afford BW.2. The sulfonamide nitrogen is then alkylated with an optionally substituted alkylhalide (e.g. iodomethane) or other appropriate electrophile in the presence of an inorganic base (e.g. potassium carbonate) to afford BW.3. Sonogashira coupling of BW.3 with an electron-rich acetylene (e.g. tetrahydro-2-(2-propynyloxy)-2H-pyran) provides the corresponding alkynyl derivative of the formula BW.4. Cyclization of BW.4 in the presence of a base (e.g. sodium hydride) affords the benzothiazin-4-one dioxide BW.5. Treatment of BW.5 with a benzylisocyanate (e.g. 4-chlorobenzylisocyanate) as above affords compounds of the formula BW.6. Deprotection of the tetrahydropyran protecting group employing standard conditions (Green, T. W.; Wuts, P. G. M. Protective Groups in Organic Synthesis, 1999) affords derivatives of the formula BW.7. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords BW.8. 
W14.1. 4H-1,4-Benzothiazine-2-carboxamide 1-oxides. Specific examples of heterocycle W14.1 in which G=morpholinylmethyl are prepared as described in Chart BB. 6-Bromo-2-benzothiazolinone BB.1 is transmetallated utilizing n-butyllithium and following the addition of methyl cyanoformate affords ester BB.2. The resulting ester BB.2 is then converted under standard conditions to the amide BB.3 by hydrolysis and amide coupling. Amide BB.3 is then reduced with lithium aluminum hydride to afford the thiol BB.4. The thiol is then cyclized with methyl 2-bromo-3-methoxyacrylate (WO 94/24085) to afford the ester BB.5. The ester is then converted to the benzyl amide followed by m-CPBA oxidation to the sulfoxide BB.6. 
W14.4. 1H4,1,2-benzothiadiazine-3-carboxamide 4,4-dioxides. As shown in Chart BX, desired benzothiadiazine4,4-dioxides are prepared from the known nitrophenylthioacetic ester BX.1 (available by the method of R. T. Coutts et. al. Can. J. Chem., 48, 1970, 3727-3732). Oxidation of sulfur using m-chloroperoxybenzoic acid or another suitable oxidant gives sulfone BX.2 which is reduced to amine BX.3 by catalytic hydrogenation using palladium on carbon and hydrogen gas or by another suitable reducing methodology. Treatment of BX.3 with sodium nitrite in acetic acid results in formation of cyclic product BX.4 which is alkylated at N-1 with iodomethane (R=CH3) in DMF and K2CO3 at 25xc2x0 C. or with some other suitable alkylating agent to give BX.5 (R=alkyl, substituted alkyl). Compound BX.5 is brominated for example with N-bromosuccinimide initiated by light in a suitable solvent such as dichloroethane to obtain the benzyl bromide BX.6 which can be reacted with morpholine to obtain compound BX.7. Finally, ester BX.7 can be reacted with 4-chlorobenzylamine, for example at elevated temperature in methanol with a trace of sodium methoxide or via another suitable amide formation route, to give desired products of the formula BX.8. 
W14.8. 1H-thieno[2,3-e][1,3,4]thiadiazine-3-carboxamide 4,4-dioxide. Preparation of specific examples of heterocycle W14.8 follows an established precedent for the corresponding ring synthesis (J. Heterocycl. Chem. 1998, 35, 933-938), Chart BC. Aminothiophene BC.1 is prepared as described in the literature (Stephens, C. E.; Sowell, J. W. J. Heterocyclic Chem. 1998, 35, 933.). Condensation of this ester with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) at high temperatures affords amides of the formula BC.2. Treatment of this amine with sodium nitrite in acetic acid provides thienothiadiazine BC.3. Bromination of BC.3 with N-bromosuccinimide affords BC.4. Examples where G=CH2NR1R2 are then prepared from BC.4 by formylation with PdCl2(PPh3)2, carbon monoxide, and sodium formate in DMF to give BC.5 according to the procedure of Okano (Bull Chem Soc Jpn 1994, 67, 2329. This material is subjected to reductive amination conditions with a primary or secondary amine (e.g. morpholine) to afford BC.6 which is then subjected to alkylation at nitrogen to provide BC.7 by well know methods to those skilled in the art. 
Specific examples of heterocycle W14.8 where G=3-hydroxypropyl or 3-hydroxy-1-propynyl are prepared as described in Chart BD. From intermediate BC.3, alkylation of the nitrogen is achieved using iodomethane and a carbonate base (e.g. potassium carbonate) in DMF giving compound BD.1. Bromination on the thiophene ring using NBS in DMF at room temperature provides compound BD.2. This material is then coupled with an electron-rich acetylene (e.g. propargyl alcohol, Z=CH2OH) catalyzed by PdCl2(PPh3)2 and copper(I)iodide either in diethylamine (Sonogashira, K.; Tohada, Y.; Hagihara, N. Tetrahedron Lett. 1975, 50, 4467.) or in a mixture of DMF and triethylamine (Fisher, M. J. et. al. J. Med. Chem. 1997, 40, 2085.) to provide the corresponding alkynyl derivative BD.3. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords derivatives of the formula BD.4. 
W16.1. 4,7-Dioxo-1,4,7,8-tetrahydro[1,8]naphthyridine-3-carboxamide. The preparation of specific examples of heterocycle W16.1 is described in Chart BE. 2-Amino-4-bromopyridine BE.1 is reacted with Boc-anhydride in dichloromethane toafford BE.2. The resulting Boc-protected amine is then oxidized with peroxybenzoic acid (Justus Liebigs Ann. Chem. 1972, 758, 111) to afford hydroxypyridine BE.3. The pyridyl nitrogen is then alkylated in the presence of potassium carbonate and iodomethane with acetone as solvent to afford BE.4. The Boc group is then removed under standard deprotection condition to afford BE.5. The pyrimidone BE.5 is then cyclized with methyl 2-(((4-chlorobenzyl)amino)carbonyl)-3-methoxy-2-propenoate to afford naphthyridine BE.6. Reaction of BE.6 with an alkylating agent (e.g. iodomethane) in the presence of potassium carbonate with acetone as solvent affords compounds such as BE.7. Compound BE.7 is then coupled through a modified Sonogashira coupling (Linstrumelle, G.; et. al, Tetrahedron Lett, 1993, 34 6403) with an electron-rich acetylene (e.g. propargyl alcohol, Z=CH2OH) to afford the alkyne derivative BE.8. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives of formula BE.9 (Z=CH2OH). 
Specific examples of heterocycle W16.1 in which G=CH2NR1R2 are prepared as described in Chart BF. Naphthyridine BE.7 is coupled under modified Negishi coupling conditions with vinylzinc in the presence of Pd(PPh3)4 (Palmgren, A.; et. al. J. Org. Chem. 1998, 63, 3764) to afford the vinyl derivative BF.1. Oxidative cleavage of the olefin with osmium tetroxide and sodium periodiate provides the aldehyde BF.2. The resulting aldehyde is then reacted under reductive amination conditions with a primary or secondary amine (e.g. morpholine) in the presence of acetic acid and sodium cyanoborohydride to afford compounds such as BF.3. 
W17. 4-Oxo-4H-pyrido[2,1-c][1,2,4]triazine-3-carboxamide. Preparation of specific examples of heterocycle W17 follows an established literature precedent described in Chart BG (U.S. Pat. No, 4,081,545). 2-Hydrazino-5-iodopyridine BG.1 is condensed with diethyl ketomalonate and subjected to thermal cyclization in 1,2,4-trichloroethane to provide pyridotriazine ester BG.2. The resulting ester BG.2 is then treated with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) at high temperature to afford the corresponding amides of the general formula BG.3 or ester BG.2 may be saponified to afford the corresponding acid which is then coupled with a benzylamine mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to provide amides of the general formula BG.3. Sonogashira coupling of BG.3 with an electron-rich acetylene (e.g. propargyl alcohol, Z=CH2OH) provides the alkynes of the general formula BG.4. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords the corresponding alkyl derivatives of the formula BG.5. 
Specific examples of heterocycle W17 in which G=4-morpholinylmethyl are prepared as described in Chart BH. Palladium catalyzed carbonylation of BG.3 in the presence of tributyltin hydride gives the corresponding aldehyde BH.1. Reductive amination of the resulting aldehyde with a primary or secondary amine (e.g. morpholine) and sodium cyanoborohydride affords the aminomethyl substituted derivatives such as those of formula BH.2. 
W18. 4-Hydroxy-1-benzothiophene-5-carboxamides. The preparation of specific examples of heterocycle W18 is described in Charts BI. 6,7-dihydro-1-benzthiophen-4(5H)one BI.1 is deprotonated alpha to the carbonyl by treatment with LDA at low temperature. The resulting enolate is then quenched with HMPA and methylcyano-formate (Mander, L. N.; Sethi, S. P. Tetrahedron. Lett. 1983, 24, 5425-5428.) to give xcex2-ketoester BI.2. Bromination of BI.2 with an electophilic bromine source (e.g. bromine) provides bromide BI.3. Elimination of BI.3 is achieved using lithium carbonate in DMF at 100xc2x0 C. to give benzothiophenol BI.4. Heating BI.4 in excess benzylamine (e.g. 4-chlorobenzylamine) gives amide BI.5. Treatment of BI.5 with the Mannich reagent 4-methylenemorpholin-4-ium chloride in refluxing acetonitrile (Dowle, M. D.; Hayes, R.; Judd, D. B.; Williams, C. N. Synthesis, 1983, 73-75.) affords compounds of the general formula BI.6. 
Other specific examples of heterocycle W18 in which G=3-hydroxypropyl or 3-hydroxy-1-propynyl are prepared as described in Chart BJ. Bromination of BI.5 adjacent to the sulfur using NBS in DMF affords the bromide BJ.1. Sonogashira coupling of BJ.1 with propargyl alcohol catalyzed by PdCl2(PPh3)2 and copper(I) iodide either in diethylamine (Sonogashira, K.; Tohada, Y.; Hagihara, N. Tetrahedron Lett. 1975, 50, 4467.) or in a mixture of DMF and triethylamine (Fisher, M. J. et. al. J. Med. Chem. 1997, 40, 2085.) provides the corresponding alkynes of the general formula BJ.2. Saturation of these alkynes by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives BJ.3. 
W19.1. 5-Hydroxy-5H-[1,3]thiazolo[3,2-a]pyrimidine-6-carboxamides. Specific examples of heterocycle W19.1 are prepared as described in Chart BK. Allylic bromination of thiazolopyrimadine BK.1 employing N-bromosuccinimide and benzoyl peroxide affords the halide BK.2. Displacement of the bromide leaving group by morpholine provides BK.3. The resulting ester is then saponified to afford the corresponding acid which is then coupled with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to provide amides of the general formula BK4. 
W19.2. 5-Hydroxy-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidine-6-carboxamides. As described in Chart BL, (4-morpholinyl)acetic acid trifluoroacetic acid salt BL.1 (J. Med. Chem. 1994, 37, 4538-4554) is cyclized to the thiadiazole BL.2 with aminoguanidine in polyphosphoric acid. Condensation of BL.2 with diethyl ethoxymethylenemalonate followed by thermal cyclization affords thiadiazolopyrimidine BL.3. The resulting ester BL.3 is then saponified to afford the corresponding acid BL.4 which is then coupled with a benzylamine (e.g. 4-chlorobenzylamine) mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to provide amides of the general formula BL.5. A specific example of heterocycle W19.2 in which R8=OH is also prepared as described in Chart BL. Thiadiazole BL.2 is heated in xylenes with diethyl 2-(((4-chlorobenzyl)amino) carbonyl)malonate (prepared by the reaction of 4-chlorobenzyl-amine with triethyl methanetricarboxylate) to afford thiadiazolopyrimidine BL.6. 
W20.1. 7-Oxo-4,7-dihydro[1,3]thiazolo[5,4-b]pyridine-6-carboxamides. Preparation of specific examples of heterocycle W20.1 follows an established literature precedent described in Chart BM (A. Haemers J. Heterocyclic Chem. 1984, 21, 401-406.). Morpholine is condensed with chloroacetyl chloride to afford 4-(chloroacetyl)-morpholine (BM.1) which is transformed to the dithiocarboxylate methyl ester (BM.2) by the reaction with sulfur, an amine base (e.g. triethylamine) and iodomethane. Condensation of BM.2 with aminoacetonitrile bisulfate in the presence of triethylamine affords the thiazole BM.3. Subsequent reduction of the carboxamide with borane provides BM.4 which is condensed with diethyl ethoxymethylenemalonate to give BM.5. Alkylation of the enamine nitrogen with an alkylhalide (e.g. iodomethane) or other suitable electrophile in the presence of an inorganic base affords BM.6. Cyclization of BM.6 by heating in a mixture of Eaton""s reagent provides the thiazolopyridine BM.7. The resulting ester is then treated with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) at high temperature or the ester may be saponified to afford the corresponding acid which is then coupled with a benzylamine mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to provide amides of the general formula BM.8. 
W20.2. 4-Oxo-1,4-dihydrothieno[2,3-c]pyridazine-3-carboxamides. Preparation of specific examples of heterocycle W20.2 follows an established literature precedent described in Chart BN-BO (J. Prakt. Chem. 1997, 339, 284-287.). As described in Chart BN, diazotization of xcex2-ketoesters BN.1 (prepared as described in Chart BQ, where Y=4-morpholiylmethyl; Chart BR, where Y=bromo) with tosyl azide provides BN.2. Reductive cyclization of BN.2 with triphenylphosphine affords the thienopyridazine BN.3. The ring nitrogen atom of compound BN.3 may then be optionally substituted by a group R inclusive to the group R7 consisting of a substituted or unsubstituted, alkyl or cycloalkyl group by reaction of BN.3 in the presence of a base and a species R-leaving group (e.g. iodomethane) or by the reaction of BN.3 with a species ZOH (e.g. methanol) under Mitsunobu conditions (Synthesis 1981, 1) to afford compounds of the formula BN.4. Esters BN.3 or BN.4 are then treated with a benzylamine (e.g. 4-chlorobenzylamine, 4-bromobenzylamine, or 4-fluorobenzylamine) at high temperature to afford the corresponding amides of the general formula BN.5, or alternatively, the ester is saponified to afford the corresponding acid which is then coupled with a benzylamine mediated by 1,1xe2x80x2-carbonyldiimidazole (or other suitable carboxylic acid activating agent) to likewise provide amides of the general formula BN.5. 
In another aspect, specific examples of heterocycle W20.2 in which R7=aryl or het are prepared as described in Chart BO. Treatment of compounds of the formula BN.1 with an aryl- or heteroaryldiazonium chloride affords the hydrazone BO.1. Hydrazone BO.1 cyclizes to afford the thienopyridazine BO.2 upon treatment with an appropriate base (e.g. potassium carbonate). The resulting ester may be transformed to the corresponding carboxamides of the general formula BO.3 in a similar fashion to that described in Chart BN. 
As specified in Chart BN and Chart BO, when Y=bromo, intermediates BN.5 or BO.3 may be further elaborated to provide specific examples of heterocycle W4.1 where G=3-hydroxypropyl or 3-hydroxy-1-propynyl as described in Chart BP. Intermediates BN.5 and BO.3 undergo Sonogashira coupling with an electron-rich acetylene (e.g. propargyl alcohol, Z=CH2OH) catalyzed by PdCl2(PPh3)2 and copper(I) iodide either in diethylamine (Sonogashira, K.; Tohada, Y.; Hagihara, N. Tetrahedron Lett. 1975, 50, 4467.) or in a mixture of DMF and triethylamine (Fisher, M. J. et. al. J. Med. Chem. 1997, 40, 2085.) provides the corresponding alkynyl derivatives of formula BP.1 (Z=CH2OH). Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords alkyl derivatives of formula BP.2 (Z=CH2OH). 
BN.1 (Y=morpholinylmethyl) is prepared according to Chart BQ. Metalation of 3-bromo-2-chlorothiophene BQ.1 (U.S. Pat. No. 5,276,025) at low temperature with lithium diisopropylamide followed by quenching with N,N-dimethylformamide and acid work-up provides thiophenecarboxaldehyde BQ.2. Reductive amination of BQ.2 with morpholine, acetic acid, and sodium triacetoxyborohydride provides the morpholinylmethyl BQ.3. Metal-halogen exchange between n-butyllithium and BQ.2 at xe2x88x9270xc2x0 C. in diethyl ether followed by addition of the resulting aryl lithium to N-methoxy-N-methylacetamide yields the methylketone BQ.4. Treatment of BQ.4 with a base (e.g. sodium hydride) in the presence of diethylcarbonate affords the xcex2-ketoester BN.1 (Y=morpholinylmethyl) which may then be employed as in Chart BN. 
BN.1 (W=bromo) is prepared according to Chart BR. Conversion of 2-chloro-5-bromo-3-thiophenecarboxylic acid BR.1 (WO 97/11705) to its corresponding Weinreb amide with N,O-dimethylhydroxylamine according to established procedures (Einhon, J.; Einhon, C.; Luche, J. L. Syn. Commun. 1990, 20, 1105-1112) followed by treatment with methylmagnesium bromide provides the methylketone BR.2. Treatment of BR.2 with a base (e.g. sodium hydride) in the presence of diethylcarbonate affords the xcex2-ketoester BN.1 (W=bromo) which may be employed as in Chart BN. 
W22.2. 4-Hydroxy-1H-thieno[2,3-c][1,2]thiazine-3-carboxamide-2,2-dioxides. Representative examples of heterocyle W22.2 (G=3-hydroxy-1-propynyl or 3-hydroxypropyl) are prepared as described in Chart BS. Methyl 2-aminothiophene-carboxylate (BS.1) is converted to the corresponding sulfonamide with methane-sulfonyl chloride to afford BS.2. The sulfonamide nitrogen is then alkylated with an optionally substituted alkylhalide (e.g. iodomethane) or other appropriate electrophile in the presence of an inorganic base (e.g. potassium carbonate) to afford BS.3. Cyclization of BS.3 in the presence of a base (e.g. sodium hydride) affords the thieno-thiazine dioxide BS.4. The resulting product is then iodinated employing mercury(II) oxide and iodine or under similar halogenation conditions to afford iodide BS.5. Sonogashira coupling of BS.5 with an electron-rich acetylene (e.g. tetrahydro-2-(2-propynyloxy)-2H-pyran) provides the corresponding alkynyl derivative of the formula BS.6. Treatment of BS.6 with a benzylisocyanate (e.g. 4-chlorobenzylisocyanate) affords compounds of the formula BS.7. Deprotection of the tetrahydropyran protecting group employing standard conditions (Green, T. W.; Wuts, P. G. M. Protective Groups in Organic Synthesis, 1999) affords derivatives of the formula BS.8. Saturation of the alkyne by hydrogenation catalyzed by palladium on carbon in alcoholic solvents affords BS.9. 
The inventive compounds may be used in their native form or as salts. In cases where compounds are sufficiently basic or acidic to form stable nontoxic acid or base salts, administration of the compounds as salts may be appropriate. Examples of pharmaceutically acceptable salts are organic acid addition salts formed with acids which form a physiological acceptable anion, for example, tosylate, methanesulfonate, acetate, citrate, malonate, tartarate, succinate, benzoate, ascorbate, etoglutarate, and glycerophosphate. Suitable inorganic salts may also be formed, including hydrochloride, sulfate, nitrate, bicarbonate, and carbonate salts.
Pharmaceutically acceptable salts may be obtained using standard procedures well known in the art, for example by reacting a sufficiently basic compound such as an amine with a suitable acid affording a physiologically acceptable anion. Alkali metal (for example, sodium, potassium or lithium) or alkaline earth metal (for example calcium) salts of carboxylic acids can also be made.
Compounds of the present invention can conveniently be administered in a pharmaceutical composition containing the compound in combination with a suitable excipient, the composition being useful in combating viral infections. Pharmaceutical compositions containing a compound appropriate for antiviral use are prepared by methods and contain excipients which are well known in the art. A generally recognized compendium of such methods and ingredients is Remington""s Pharmaceutical Sciences by E. W. Martin (Mark Publ. Co., 15th Ed., 1975). The compounds and compositions of the present invention can be administered parenterally (forexample, by intravenous, intraperitoneal or intramuscular injection), topically (including but not limited to surface treatment, transdermal application, and nasal application), intravaginally, orally, or rectally, depending on whether the preparation is used to treat internal or external viral infections.
For oral therapeutic administration, the active compound may be combined with one or more excipients and used in the form of ingestible tablets, buccal tablets, troches, capsules, elixirs, suspensions, syrups, wafers, and the like. Such compositions and preparations should contain at least 0.1% of active compound. The percentage of the compositions and preparations may, of course, be varied and may conveniently be between about 2 to about 60% of the weight of a given unit dosage form. The amount of active compound in such therapeutically useful compositions is such that an effective dosage level will be obtained.
The tablets, troches, pills, capsules, and the like may also contain the following: binders such as gum tragacanth, acacia, corn starch or gelatin; excipients such as dicalcium phosphate; a disintegrating agent such as corn starch, potato starch, alginic acid and the like; a lubricant such as magnesium stearate; and a sweetening agent such as sucrose, fructose, lactose or aspartame or a flavoring agent such as peppermint, oil of wintergreen, or cherry flavoring may be added. When the unit dosage form is a capsule, it may contain, in addition to materials of the above type, a liquid carrier, such as a vegetable oil or a polyethylene glycol. Various other materials may be present as coatings or to otherwise modify the physical form of the solid unit dosage form. For instance, tablets, pills, or capsules may be coated with gelatin, wax, shellac or sugar and the like. A syrup or elixir may contain the active compound, sucrose or fructose as a sweetening agent, methyl and propylparabens as preservatives, a dye and flavoring such as cherry or orange flavor. Of course, any material used in preparing any unit dosage form should be pharmaceutically acceptable and substantially non-toxic in the amounts employed. In addition, the active compound may be incorporated into sustained-release preparations and devices such as the osmotic release type devices developed by the Alza Corporation under the OROS trademark.
The compounds or compositions can also be administered intravenously or intraperitoneally by infusion or injection. Solutions of the active compound or its salts can be prepared in water, optionally mixed with a nontoxic surfactant. Dispersions can also be prepared in glycerol, liquid polyethylene glycols, triacetin, and mixtures thereof and in oils. Under ordinary conditions of storage and use, these preparations contain a preservative to prevent the growth of microorganisms.
Pharmaceutical dosage forms suitable for injection or infusion can include sterile aqueous solutions or dispersions or sterile powders comprising the active ingredient which are adapted for the extemporaneous preparation of sterile injectable or infusible solutions or dispersions, optionally encapsulated in liposomes. In all cases, the ultimate dosage form should be sterile, fluid and stable under the conditions of manufacture and storage. The liquid carrier or vehicle can be a solvent or liquid dispersion medium comprising, for example, water, ethanol, a polyol (for example, glycerol, propylene glycol, liquid polyethylene glycols, and the like), vegetable oils, nontoxic glyceryl esters, and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the formation of liposomes, by the maintenance of the required particle size in the case of dispersions or by the use of surfactants. The prevention of the action of microorganisms can be brought about by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, thimerosal, and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars, buffers or sodium chloride. Prolonged absorption of the injectable compositions can be brought about by the use in the compositions of agents delaying absorption, for example, aluminum monostearate and gelatin.
Sterile injectable solutions can be prepared by incorporating the active compound in the required amount in the appropriate solvent with various of the other ingredients enumerated above, as required, followed by filter sterilization. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and the freeze drying techniques, which yield a powder of the active ingredient plus any additional desired ingredient present in the previously sterile-filtered solutions.
For topical administration, the present compounds may be applied in pure form, i.e., when they are liquids. However, it will generally be desirable to administer them to the skin as compositions or formulations, in combination with a dermatologically acceptable carrier, which may be a solid or a liquid.
Useful solid carriers include finely divided solids such as talc, clay, microcrystalline cellulose, silica, alumina and the like. Useful liquid carriers include water, alcohols or glycols or water-alcohol/glycol blends, in which the present compounds can be dissolved or dispersed at effective levels, optionally with the aid of non-toxic surfactants. Adjuvants such as fragrances and additional antimicrobial agents can be added to optimize the properties for a given use. The resultant liquid compositions can be applied from absorbent pads, used to impregnate bandages and other dressings, or sprayed onto the affected area using pump-type or aerosol sprayers. Thickeners such as synthetic polymers, fatty acids, fatty acid salts and esters, fatty alcohols, modified celluloses or modified mineral materials can also be employed with liquid carriers to form spreadable pastes, gels, ointments, soaps, and the like, for application directly to the skin of the user.
Examples of useful dermatological compositions which can be used to deliver the compounds of formula I to the skin are known to the art; for example, see Jacquet et al. (U.S. Pat. No. 4,608,392), Geria (U.S. Pat. No. 4,992,478), Smith et al. (U.S. Pat. No. 4,559,157) and Wortzman (U.S. Pat. No. 4,820,508).
Useful dosages of the compounds of formula I can be determined by comparing their in vitro activity, and in vivo activity in animal models. Methods for the extrapolation of effective dosages in mice, and other animals, to humans are known to the art; for example, see U.S. Pat. No. 4,938,949.
The compound is conveniently administered in unit dosage form; for example, containing 5 to 1000 mg, conveniently 10 to 750 mg, most conveniently, 50 to 500 mg of active ingredient per unit dosage form. The desired dose may conveniently be presented in a single dose or as divided doses administered at appropriate intervals, for example, as two, three, four or more sub-doses per day. The sub-dose itself may be further divided, e.g., into a number of discrete loosely spaced administrations; such as multiple inhalations from an insufflator or by application of a plurality of drops into the eye.
For internal infections, the compositions can be administered orally or parenterally at dose levels, calculated as the free base, of about 0.1 to 300 mg/kg, preferably 1.0 to 30 mg/kg of mammal body weight, and can be used in man in a unit dosage form, administered one to four times daily in the amount of 1 to 1000 mg per unit dose.
For parenteral administration or for administration as drops, as for eye infections, the compounds are presented in aqueous solution in a concentration of from about 0.1 to about 10%, more preferably about 0.1 to about 7%. The solution may contain other ingredients, such as emulsifiers, antioxidants or buffers.
Generally, the concentration of the compound(s) of formula I in a liquid composition, such as a lotion, will be from about 0.1-25 wt-%, preferably from about 0.5-10 wt-%. The concentration in a semi-solid or solid composition such as a gel or a powder will be about 0.1-5 wt-%, preferably about 0.5-2.5 wt-%.
The exact regimen for administration of the compounds and compositions disclosed herein will necessarily be dependent upon the needs of the individual subject being treated, the type of treatment and, of course, the judgment of the attending practitioner. The compounds of the present invention can be administered to an animal in need of treatment. In most instances, this will be a human being, but the treatment of livestock and companion animals is also specifically contemplated as falling within the scope of the instant invention.
The compounds of formula (I) and pharmaceutically acceptable salts thereof are useful as antiviral agents. Thus, they are useful to combat viral infections in animals, including man. The compounds are generally active against herpesviruses, and are particularly useful against the varicella zoster virus, the Epstein-Barr Virus, the herpes simplex virus types 1 and 2 (HSV-1 and 2), the human herpes virus types 6, 7 and 8 (HHV-6, 7and 8) and the human cytomegalovirus (HCMV).
The invention will be further described by the following non-limiting examples.
2-Amino-5-iodopyridine [Y.2].
A mixture of 2-aminopyridine (4.0 g), periodic acid dihydrate (1.94 g), and iodine (4.31 g) is heated in a solution of acetic acid (25.5 mL), water (5.1 mL), and sulfuric acid (0.76 mL) at 80xc2x0 C. for 4 h. The reaction is allowed to cool to room temperature, then poured into 300 mL of a dilute solution of sodium bisulfite. An orange solid precipitates and is filtered and discarded. The filtrate is neutralized (pH xcx9c5-6) with saturated NaHCO3 and then partitioned against CH2Cl2. The aqueous layer is further washed with CH2Cl2 (2xc3x97). The combined organic layers are dried (Na2SO4), filtered, and condensed to afford a solid. The crude product is recrystallized from ether/hexanes to afford 2.69 g (29%) of the title compound as a yellow solid. Physical characteristics: m.p. 126-129xc2x0 C.; 1H NMR (300 MHz, DMSO-d6) xcex4 8.04, 7.58, 6.35, 6.13; MS (ESI+) m/z 221 (M+H)+; Anal. found: C, 27.40; H, 2.06; N, 12.75.
Ethyl 7-iodo-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxylate [Y.3].
In a 3-necked round-bottom connected to a Dean-Stark trap, a solution of 2-amino-5-iodopyridine (Preparation 1, 500 mg) and diethyl ethoxymethylenemalonate (0.92 mL) is heated at 130xc2x0 C. for 2 h. The reaction is cooled to room temperature. Diphenyl ether (5 mL) is added and the reaction is heated at 250xc2x0 C. for 1 h. Upon cooling the mixture to room temperature, a solid precipitates and is filtered and washed with hexanes. The crude solid is adsorbed onto silica and chromatographed eluting with CH2Cl2 (2 L). Product-containing fractions are combined and concentrated to afford a solid. The crude product is recrystallized from CH2Cl2/hexanes to yield 251 mg (32%) of the title compound as a yellow solid. Physical characteristics: m.p. 166-168xc2x0 C.; 1H NMR (300 MHz, DMSO-d6) xcex4 9.24, 8.85, 8.38, 7.62, 4.27, 1.30; IR (drift) 1747, 1611, 1558, 1506, 1473, 1355, 1345, 1291, 1266, 1258, 1152, 1140, 1118, 840, 796 cmxe2x88x921; MS (ESI+) m/z 345; Anal. found: C, 38.37; H, 2.48; N, 8.11.
N-(4-chlorobenzyl)-7-iodo-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxamide [Y.4].
To a solution of 4-chlorobenzylamine (0.071 mL) in toluene (1.5 mL) at 0xc2x0 C. is added trimethylaluminum (2M solution in toluene, 0.29 mL). After stirring the solution at 0xc2x0 C. for 5 min, ethyl 7-iodo-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxylate (Preparation 2, 200 mg) is added. The solution is stirred at 0xc2x0 C. for an additional 10 min, then allowed to stir at room temperature overnight. The reaction mixture is poured into 3 N HCl (7.5 mL) and water, then extracted with CH2Cl2 (3xc3x97). The combined organic layers are dried (Na2SO4), filtered, and concentrated to afford a solid. The impurities are removed by dissolving the crude product in CH2Cl2 and filtering the insoluble solid. The filtrated is concentrated to afford 148 mg (58%) of title compound as a yellow solid. Physical characteristics: m.p. 191-194xc2x0 C.; 1H NMR (300 MHz, DMSO-d6) xcex4 9.36, 9.27, 9.03, 8.38, 7.68, 7.40, 4.57; IR (drift) 3319, 1683, 1637, 1612, 1560, 1541, 1507, 1478, 1347, 1339, 1295, 837, 792, 641, 625 cmxe2x88x921; MS (ESI+) m/z 440 (M+H)+; Anal. found: C, 43.58; H, 2.48; N, 9.38.